Paxiled's right...Wellbutrin is indeed a stimulating anti-depressant. I'm on it myself (5 years,plus Celexa for 7 years, plus Zoloft for 5 yrs before that---Phew! ).
And as Paxiled said, diagnosis is a tricky thing.
I often wonder if the Docs can get it 100% right or not!?
Still, since I'm still alive & kicking, I've learned to kind of "go with it". I lead a very good life now, so I suppose something did work in the long run for me. I think things can work for you too!
PLZ NOTE: My diagnosis , according to my psychiatrist , is "recurring major depression", just like you ,Lilybird.
My Docs have tried a variety of combinations of medications before they found what works for me. However, plz note: we are all different. We all respond to these meds differently.
Being a woman myself, I noticed that as my hormones changed,then so did my need for the meds' dosages.
Since you are a woman like me, it could be that as you're aging, your meds need to be re-adjusted. This is just my humble opiniuon, but I think that for women, our hormones affect the dosages of our meds. I've seen it in myself! (As has my own husband).
My suggestion: go to your Doc, tell him of these changes in your body, and ask if you need a re-adjustment, or a new med, or to be off the meds altogether and try something else (eg: cognitive therapy, etc) .
PS:... and...if you are approaching menopause or even peri-menopause, your Doc should be reminded of this fact also.
Misdiagnoses are extremely common, because the diagnoses are devised more for insurance coverage than their importance to your treatment. Bipolar particularly has become a huge growth industry. There used to be just bipolar, now there are more forms of it than you can throw a stick at. Doubtful any of them are actually bipolar in the sense of how that disorder has traditionally been viewed. As for wellbutrin, it can be very stimulating; because of that it's not usually used, for example, for people who also suffer from anxiety. So it seems right this could be the wellbutrin.