Ick!
Well, I've read your posts on some of your other RPs (not being stalkerish, I just liking reading other things all of my partners are involved with), and I have noticed a bit of a drop of there as well of late. My suggestion is the same as before, dearie! Take a break! If it's wrenching your guts just thinking about it, take a step back.
The waking up in pain part? That's a little more alarming. It's starting to sound a lot like the clinical depression I went through a few years ago and still suffer from a bit time to time. And that can be just as serious as any disease! I know it can be hard, I hate the medical industry myself, but in this case you might just want to go see a doctor, love! Don't let anyone tell you it's 'just' depression! And if it is something more tangible, then the sooner you talk to a professional about it, the better!
In the meantime? Try going old school. Pen and notebook. Much like the artistic exercise, don't try to write anything specifically. As words come into your mind, just write them down. They don't have to connect or be meaningful or even make sense. If you see a stop sign, write down 'Red.' Taste vanilla ice cream, maybe the word 'clown' will pop into your head. Don't force it, don't worry about, just jot down individual words now and then. It takes time to get into the habit, yes, but there's no hurry, right?