As I suggested in the comment, in such case I would seek for a help/treatment immediately.
I assume that nobody will ask you for instant payment. In case of Mawista travel insurance (not a real health insurance) that you have, you can ask doctor to wait for 1-2 months (for payment, not for treatment) and clarify the issue with Mawista.
I had Mawista myself and did not have too much spare money, so asking a doctor to wait for 1-2 months for the payment until Mawista will reimburse me the costs, was usual practice for me.
The fact that your travel insurance does not cover psychoanalytic and psychotherapeutic treatment has no relation to your question in my eyes.
Psychoanalysis and psychotherapie is not a medicine, rather this is psychology. In Germany you need to differentiate between psychological psychotherapists and psychotherapeutical psychiaters:
So just go to the doctor (go to psychiatry, do not go to psychotherapeut) and clarify the payment questions with him/her. In the end, Mawista will probably ask your doctor to describe the case in the special form they will send to you. If the doctor will NOT directly write there that your current condition is related to the pre-existing problems, then with very high probability you will not have any problems with the insurance. Your doctor may also claim that your current condition is acute exacerbation of the pre-existing chronical condition, which I can expect will also be covered by Mawista. As far as I remember, different to other travel insurances, Mawista never explicitly excluded treatment of the chronical issues in their contract.
To be clear, IMHO Mawista just does not want to cover cases, such as "you were chronically ill before travelling and now you suddenly want to treat your chronic condition during your stay in Germany". If the doctor will not write this explicitly, you still should have very high chances of being covered by Mawista.
You can also consider changing the travel insurance to the proper health insurance. However, private insurances will do a health check on you and the monthly payment (much higher than for Mawista) also depends on the pre-existing conditions that you should report to them in advance. Still, you might consider paying a lot for private insurance to be fully covered.
Another option would be a publicly regulated health insurance.
If you have only the scholarship and therefore you are not currently eligible for publicly regulated health insurance, you can try to talk with your professor and/or university to get a job contract instead of the scholarship (or a mixture of scholarship and job contract). Then you will be enrolled into the publicly regulated health insurance, which will cover your issue (by the way, they also do not completely cover psychological consultations, but of course they should cover psychiatric conditions (Mawista should also do it)).
If all options mentioned above are not possible for you, and your travel insurance will not cover your case (IMHO, they will cover it), then you only have an option to get a treatment in your home country, if you won't pay on your own for the treatment in Germany.
Please also think if your condition might be related to possible stalking, bullying or abuse at the university. Then I would advice you to talk with a lawyer. My thoughts would be to sue the university (or at least your lawyer might write them a letter demanding for payment) and get the treatment paid by the university and/or abuser.
Finally, if your condition is related to your job/study, you also might be covered by some kind of insurance that university already has for all students.