Unfortunately, employers usually have higher expectations for mid-career applicants, even though they may have been job hunting a long time and may be under a lot of stress. Practice to become a polished interviewer. A good way to practice and to learn from others' interviewing techniques is to join a job-hunting club or support group. The National Business Employment Weekly published by The Wall Street Journal gives the addresses and phone numbers of many such groups. Some local sections of professional societies such as ACS and some churches sponsor job-hunting clubs or provide such clubs with a place to meet.
Some groups are part of national organizations.
For example, Forty Plus groups are located in many cities. Others are organized by state employment commissions. Some are basically seminar or coaching groups that charge fees. Even a full-time job hunt can take a year or more. Although many career counselors advise that job hunting is a full-time job, during an extended search it is often difficult to keep productively busy for forty hours a week.