Hi ~ Don't EVER stop taking any medication COLD-TURKEY!! It can be very dangerous to do and it COULD have caused seizures. Now your depression is alot worse.
You need to talk to your doctor about the fact that you stopped taking it AND you need to go back on it, perhaps with a higher dosage. Obviously it wasn't working very well, so you must need a higher dose. Do NOT DO THIS ON YOUR OWN. You must talk with your doctor first, because you'll run out early if you don't.
Also, if you have a therapist, have a good chat with him too. Your thoughts of worthlessness need to be addressed. You certainly are NOT worthless, my friend! And your bf was an absolute JERK for leaving you when you needed him for support. If I was with someone who left me at a time like that, I would certainly be glad to be rid of him! Can you believe how it would be like if the tide were turned? He'd be crying like a baby -- curled up in bed in the fetal position.

But YOU are much stronger than that --- you're reaching out to us for support, and that's great!!
So talk to your doc, and keep postiing. We'll be here. God bless & take care. Hugs, Lee