Unfortunately, if you have to ask your employers for "accommodations" because of your illnesses, they may decide that they cannot provide those accommodations for you and you may lose your job. Here is where you have to face some really difficult questions about your choice of career. Can you really handle the job? If you can't do the work, then you will have to "declare yourself" as being "disabled" to your employer -- and you will need to face those consequences.
My recommendation is for you to think seriously about the types of jobs that you can do on a consistently basis and limit your job search
to just those types of jobs. If you choose to pursue jobs that you cannot do consistently, then you will have to deal with the consequences of that decision. That's an unpleasant truth you need to face -- and forgive me if I am sounding harsh -- but it would be better for you think it all through now while you are still young and can plan a career that is in within your capabilities than to invest a lot of money, time, effort, and emotion on options that just won't work for you in the long run because of your health problems.
Also, I recommend talking with an attorney knowledgable about employment related to people with chronic health problems
. Such a person can tell you what your legal rights and obligations are -- and give you advice on how to handle the disclosure of your condition and any requests you made for special accommodations.
I wish you the best of luck with whatever career path you choose.