This is a tough question. I have been there and know exactly what it is like to be bullied by a co-worker (in my case it was my immediate supervisor, who laid blame when it was her mistake). At that time my hubby was off because it was winter, I had 3 kids to feed, and all of the bills to pay (at least our regular health insurance was covered by the provincial govt.) I ended up getting sick, relatives died, friends ended up in the hospital, so I was at an all time low, but I kept going, every morning I would get up, puke, get ready, drive to the other end of the City and work my butt off, then I would drive home. I did this in the winter when I had minimal heat in my van (just enough to keep the windows from frosting up).
Then my father-in-law ended up in the hospital, and I was on my last legs when I was laid off from my job. He passed away 2 days later. The decision was taken out of my hands and I actually felt better, for not having to make the decision myself. I know big cop out.
Now it isn't quite so bad, still there are days when I just don't want to keep going, but again, I have an out-of-work (or part-time work) hubby, and 2 kids at home, so bills and food to pay. No more sick days, so time off is unpaid. There is no leave of absence for me, unless I could miraculously get my doctor to waive the $200.00 fee she charges for filling out paper work in order for me to get sick leave insurance from the Federal Govt.
So my suggestion to you would be to keep going, one day at a time push, puke, grunt, scream whatever it takes, you are a strong person as you have come to this sight and have asked for help. It takes a wuss to ignore the issue, it takes a determined and strong person to admit there is a problem and attempt to resolve it.
Take care and keep us posted.