It can be tough when you feel like that, especially with a 60-pointer. If you think you will regain some oomph in the next couple of weeks try and get an extension. If not, you have further options like deferral/switching/ditching. These diminish/get more expensive with time so it might be worth finding out from SST what the situation is.
It's best to just find out your options, consider them all and try to pick the best one for you. Hope you feel better whatever you decide. The last time I felt like that (and zeroed a TMA) I switched subjects completely and it worked out pretty well. Others have come back from way behind/down to get what they wanted.