For urgent first aid, please use the Berlin Crisis Center (Krisendienst): https://www.berliner-krisendienst.de/en/

Or if you are thinking of harming yourself, please find 24 hour help here.

You may also find a helpful service here: https://www.berlin.de/willkommenszentrum/en/everyday-life/help-and-support/

All three Berlin Universities offer counseling and psychological services. Students may contact them to discuss a range of issues from study motivation, orientation at university, meeting deadlines and exam nerves, to study overload, homesickness, family problems, depression or any other academic or non-academic issue. The current COVID-19 pandemic has notoriously caused negative effects on students’ mental health, thus making them less motivated to study and increasing symptoms of depression and isolation.
At the first meeting, the counselor will outline what steps can be taken to solve a specific problem. Further appointments can be made or else the counselor will help the student to find a therapist if necessary. The counseling sessions are strictly confidential.
https://www.fu-berlin.de/en/sites/studienberatung/psychologische_beratung/
https://www.hu-berlin.de/en/studies/counselling/psyber
https://www.studienberatung.tu-berlin.de/menu/beratung/psychologische_beratung/parameter/en/

If you are seeking long-term/ regular psychotherapy, you will need to contact a psychologist or general practitioner first to get a diagnosis. It may also help to contact your health insurance provider to ask for advice on finding the right doctor or therapist and how to get the therapy covered by your insurance. For individual counseling, Berlin offers a wide range of English-speaking psychotherapists. Depending on your nationality, it is also very likely to find a therapist speaking your mother tongue in Berlin. However, it is quite difficult to find a therapist who is not at full capacity. Public health insurance typically covers the cost of psychotherapy, however, it may take a few weeks (or even months) to get a cost plan and find a therapist. You should always double check with your therapist whether they are covered by public health insurance, what kind of reimbursements are possible or whether you have to pay privately.

Two BMS students took the time to collect all information on how to find help for your mental health in this pdf: Guide

https://www.scholar-minds.net
https://www.zeit.de/gesundheit/2021-07/psychotherapie-psychische-erkrankungen-therapieplatz-finden-therapiearten-kostenuebernahme-tipps/
https://psych-info.de/

You can also find some apps that might help you get a therapist or offer courses, however, these are mostly in German and not for free:
https://www.selfapy.com
https://de.deprexis.com

Information in German: https://www.psychotherapeutenkammer-berlin.de/ratsuchende/psychotherapie