In deciding "should I become self-employed," and what kind of business best suits you -- freely explore all of your options.
An excellent way to identify businesses likely to fit your personality is to take the Career Key S-E entrepreneur test. You will identify occupations-businesses that you will want to explore. For example, if "Optometrist" is one of them, you will learn of other similar ones: chiropractors, dentists, physicians, psychologists, and veterinarians.
A second way is to seek advice from others. Ask them for suggestions. Go beyond your immediate friends. Brainstorm. Be imaginative, "Who might have some good ideas?"
Third, go to the section Learn about Occupations. Many of the suggested activities will help you expand your options.
And, finally, consider how you are thinking about your decision. Can it be thought about differently? For example, instead of focusing on a long term decision, like "What career should I choose?", it might be better to put that decision off until later, when you know more. Instead, you might want to focus on a short-term decision like, "What course/major/training program best fits me?"