(1) go to a GP (Hausarzt) and explain my situation so they fill up a report and confirm that the issue is indeed psychological and not physical,
(2) go to a therapist that works with public insurance so they can write another report, your therapist might refer you to one of his/her colleagues, and
(3) email five therapists that work with public insurance and ask them how long their waiting list is. They likely will all tell you it's longer than 3 months, which is what you need to hear.
You basically send this stuff to your insurance company and they deal with the rest.
Even if you don’t improve for 100 days straight, small successes accumulate. In a decade you will have transformed yourself.
There is just no way you won’t improve significantly if you keep trying new things and bring yourself to fail ever day.
What helped me was the saying “your first million words are gonna be shit”. I still distinctly remember, four or five years into writing every day, when things finally clicked, my voice came through, and my sentences became fun. It is delayed gratification to the max.