I've been off paxil (paroxetine) for three weeks now and have plunged inte a tearful wreck....what now?

Did you go off cold: turkey? If yes, that can make a person very ill. This doesn't list any mental health conditions -so not sure why you have been taking it. If for depression - the depression may have been inadequately treated with a need to go back on the medication. If you have taken yourself off without medical supervision - that would be a serious mistake. Paxil (paroxetine) should always be tapered when it is being stopped.