What was going on when I was born?

WASHINGTON SEVERE anxiety disorders that disrupt the lives of millions of adult Americans are attracting increased attention from Federal health officials. Some victims of these disorders suffer from irrational fears of a variety of objects and situations, such as insects, mice, or riding on elevators. Others experience sudden panic attacks marked by intense fear and feelings of impending doom - or a more persistent anxious mood that may last for months. And still others suffer stress following a psychologically traumatic event, such as rape, military combat, or disastrous accidents.

A story of crimes, intrigues and murders inside ''the Bonanno family'' began to unfold yesterday as an undercover agent testified in public, for the first time, about his infiltration of organized crime. For five years, the agent worked in the underworld in the guise of a gangster using the name Donnie Brasco, but he appeared on the witness stand in a major Manhattan trial as Special Agent Joseph D. Pistone of the Federal Bureau of Investigation. A Federal prosecutor, Barbara S. Jones, asked Mr. Pistone what undercover assignment the F.B.I. gave him in 1976. ''To identify and infiltrate 'fences' associated with organized crime in New York City,'' the agent replied. ''I was a burglar, a jewel thief,'' he continued, explaining the role he played when he first met Bonanno family members in front of a social club on Madison Street in lower Manhattan.

Interest rates declined yesterday, cheering a depressed stock market and pushing the Dow Jones industrial average up by 13.51 points, matching its best gain in more than four months. The nation's banks cut the prime interest rate a half-point, to 15 percent, the lowest level in more than two years.

International President Reagan pressed Israel and the other combatants to halt the fighting in Lebanon as a prerequisite for the success of the American negotiating mission. The President, the White House announced, told the Israeli Foreign Minister, Yitzhak Shamir, in a somber 20-minute meeting that it is crucial to end th ''constantly escalating violence'' and to provide food and medical supplies to west Beirut. (Page A1, Column 6.) Israel moved tank reinforcements into all crossing points between east and west Beirut while inching its armor closer to the Palestinian camps on the city's outskirts. (A6:1-3.)

Michael and Darlene Hillman represent the sort of all-American success story that, in recent years, became commonplace in this misty land of Cajuns, alligators, oil and gas. In just three years, the former Louisiana State University football star, now 35 years old, and his wife built a petroleum-related boat business consisting of 24 barges, 16 tugs, 10 crew boats and a utility boat. Six months ago, they often had to rent even more boats to handle their surging business. No longer. Instead of the four or five jobs a day that the Hillmans' Bengal Marine Inc. had been handling for the oil industry, they are now hustling to land three or four a week. Drilling has slipped precipitously, the cash flow of independent wildcatters has dropped like a sinker and service companies like Bengal are having more and more trouble paying bills.

Senior officials of the Continental Illinois Corporation met with securities analysts yesterday in an effort to restore confidence in the bank, and according to reports from those who attended, the attempt was largely successful. The press was barred from the meetings, but analysts reported afterward that, for the first time, officials of the bank holding company disclosed details of many of their large credits to financially troubled companies. ''They actually seemed eager to talk,'' said one analyst. ''They even volunteered information about some loans without being asked.'' The Continental Illinois Corporation is the sixth-largest bank holding company in the United States and owns the Continental Illinois National Bank and Trust Company of Chicago. It has assets of $46.5 million.

An article on Saturday incorrectly reported the testimony of Sandy Golden, a freelance writer who was found by a jury on July 30 to have libeled William P. Tavoulareas, the president of Mobil Oil Corp. Mr. Golden did not testify that he had been trying to prompt a Congressional investigation of Mr. Tavoulareas.

Federal regulators today authorized 10 savings institutions, most of them financially ailing, to merge or consolidate into four separate combinations. In the largest of the new mergers, the Erie Savings Bank, of Buffalo, added more than $1.5 billion to its assets by acquiring three other thrift institutions: the American Federal Savings and Loan of Southfield, Mich.; the Harris County Federal Savings and Loan of Baytown, Tex., and the First Federal Savings and Loan of Mid-Florida, in Deland, Fla. The combination of the four associations gives the new institution, to be known as Empire Savings, $4.72 billion in assets and a total of 78 offices. The three other combinations, all of them relatively small, created institutions headquartered in Virginia, Arizona and New Jersey with total assets of about $7 billion.

SEVRES, France BY the end of next year, if international experts on measurement have their way, the basis for all measurements of distance on the earth will have been radically altered. The feet, inches and miles, or the kilometers and millimeters, of everday life are unlikely to be affected. But scientists of all sorts should rejoice if, as planned by an international panel, the length of the meter is redefined as how far light travels in a vacuum in one-299,792,458th of a second. By the same token, the speed of light would become exactly 299,792,458 meters -no more and no less - per second. By international agreement, all other units of length, such as the foot and the mile, are defined in relation to the meter. Settling the meter once and for all, as the revisers hope to do, could end centuries of international negotiation, research and redefinition of the units of length that once depended on such unstable and arbitrary standards as the length of someone's foot or of an iron bar set in the wall of a town hall somewhere.

Senior Defense Department officials said today that the Reagan Administration was undeterred by vocal Congressional opposition to military spending and that they were close to completing a 1984 military budget calling for about $247 billion in outlays. That would represent an 11 percent increase in real growth, excluding inflation, over projected spending of $209 billion in the 1983 military budget now before Congress. With inflation counted in, the new military budget would be about 17.3 percent higher. That amount would also put military spending back on the track announced last January, the officials said. Since then, President Reagan's budget compromises with Congress have suggested that military spending would dip below the 7 percent average annual increase in real growth that, the President has asserted, is needed to rebuild United States military strength.

A mental hospital report submitted today recommended that John W. Hinckley Jr. be committed for mental treatment for an indeterminate period, on the ground that he is mentally ill and dangerous to himself and others, according to sources familiar with the report. The report was submitted to Federal District Judge Barrington D. Parker, who ordered last week that it be kept secret pending a hearing scheduled for Aug. 9 on whether Mr. Hinckley qualified for release. It was compiled by two psychiatrists and a psychologist on the staff of St. Elizabeths Hospital here with assistance from other hospital personnel. Mr. Hinckley has been undergoing psychiatric evaluation at St. Elizabeths since June 22, the day after a jury found him not guilty by reason of insanity of shooting President Reagan and three other men.

An article in Business Day last Friday incorrectly identified the Raytheon Corporation as one of the major defendants involved in asbestos litigation. The company involved is the Raymark Corporation, formerly known as Raybestos Manhattan.