Wait. ((((hugs)))) You said this is the first time (in a long time?) that you have felt this depressed... which means it won't stay, imo. I suspect that it is worsened because you ARE doing all you can, and yet feel it isn't enough.

I'm glad you are letting the profs know that you are having a bit of trouble right now... no, don't give it all up, but I'm sure that you don't have 6 years hanging on this one episode..but will have credit there regardless of what happens with this semester?

Breathe. Try to distract yourself from what you feel is a good option... it is not, not now. Go through the motions until you feel better. Distance yourself and do some thought blocking to the negative stuff... I think you have done well, and will again. TC!