Wow, had the same symptoms when on 20 mg Lexapro! Reduced to 10mg & actually feel better. I don't really have an answer for you, but I certainly relate. personally I haven't tried wellbutrin yet, but am considering it. It took about 2 weeks to feel different after lowering the dose.
Wellbutrin was not a good drug for me. It caused rapid cycling and was part of the reason I was so screwed up about 2 years ago. I did much better on cipralex. I think it is a crap shoot. I would let the pdoc do the picking of drugs.
I had the same symptoms on lexapro. People w/ bipolar can actually respond opposite to some depression meds and it can even send them into a manic state - that's how my pdoc found my bipolar! I don't have any experience with wellbutrin, but I know that mood stabilizers were the only thing that ever helped me personally.
Yeah, odasi is right. If you're bipolar and you don't take a mood-stabilizer like seroquel to keep you from getting "too up", lexapro on it's own can make you very manic. Mania can cause things like anxiety, lack of sleep, not being hungry and losing weight. If lexapro has been helpful in the past when you were depressed, you can keep taking it, just take it with something that prevents mania.