I’m a little suspicious about calling it “nerve pain” while you (presumably) have unexplained bleeding. The first assumption I’d work with is that some unknown bleeding thing also hurts, and needs to be located. Sometimes two different things are going on, but more often it’s one. SteveG’s point about a peptic ulcer is right on target as a possibility, though your pain in the lower abdomen would be an unusual location for that. In any case, if Effexor makes you feel better in the interim, that’s great.