Need help! School professor asking for a mental health letter

Hey guys! So I'm in university, and struggled with a mental health episode and thus have missed a lot of class and assignments. I emailed a professor of mine to see if I could boost my grade due to my issues being out of control. I was told that I can receive full credit for my missing assignments and attendance if I get a letter from a professional stating that I have depression/anxiety.

Help!! I don't have the money to go to a professional, but I really need these points. Does anybody know if there's any way I could get in contact with a professional to write a letter for me? My issues are in the university medical system but she wants a letter specifically from a mental health professional. I do not have the money to go see somebody. Please, if anybody knows any way I could get in contact with a professional for free/very cheap, I need help to save my grades.

TLDR: I am looking for a way to get in contact with a mental health professional for little to no money due to my financial state at the moment as my professor wants a letter from a professional to raise my grade. Turning in these assignments for full marks could boost my grade up to an A.