It sounds like a good place to start might be with a psychiatrist. They can help you get a handle on the fear & crying & whatever is going on with your weight. If you are hypothyroid, you can have a low-normal BMI and still be anorexic. So by seeing a psychiatrist, they can look at all the factors & rule that in or out. But much more than that, they can help you get a hold on things. I really understand what if feels like to just feel like everything is going wrong. Thyroid issues could be causing the joint pain, weight issues, depression & a whole host of other symptoms, so it is important to rule that out first. But once you rule that out, seeing a psychiatrist may be the best short-term option. If there is something really unusual going on with your ankles & feet (osteoarthritis at your age would be very rare) it is likely to take months to get to a diagnosis. It would probably take that long for a university student in the US to get diagnosed. In Germany, you would be lucky to get referrals & tests run on you for such a rare condition for quite some time. I have talked to friends & clients in Germany who have waited 2 years to get diagnosed with pain conditions.
You can self-test for lactose intolerance. Eliminate all lactose products from your diet for 2 weeks. Here's a list of non-dairy products that can contain lactose: digestive.niddk.nih.gov/ddiseases/pubs/lactoseintolerance/#products
. If your symptoms go away, that is a good indication that you are lactose intolerant. 90% of people with lactose intolerance can benefit from taking lacta
se enzyme tablets. I know they at least have lactase tablets in Munich. I assume they are available throughout Germany. If you really want to be safe, you could just avoid lactose products until you finish your classes.
I hate to hear you say that you wish you had a chronic illness. That is an awful thing to wish for. It may mean less money in the short-term, but many people end up in financial ruin over the long run. I really hope it is just something minor -- thyroid issues, sprained ankles, something like that. There are some wonderful social service agencies in Germany that can help with financial issues. You can talk to your university adviser to locate resources. They can also advise you about
what accommodations they might be able to make to help you with your coursework.
hope that helps!