OP, you are on Thorazine, Abilify, and Seroquel? Jesus. That is a bit ridiculous IMO. Neuroleptics are not safe or healthy drugs, on the whole. They can be helpful, yes, but are detrimental to one's body and mind, and can cause irrevocable side-effects, which persist through your entire lifetime even after discontinuing them. I have, however, been on all three of those, though not ALL at the same time. I don't know all of your symptoms, and this or that, but I do know taking three neuroleptics is redundant. Taking two is heard of, as I have had experience with, but three is ridiculous. Some people are suggesting Haldol, and I suggest AGAINST it. It is extremely sedating and dysphoric, and it is more unsafe than some of the others, or at least attracts a higher incidence of side-effects.
I might suggest that you drop one of the neuroleptics, like you said you are planning on doing. That will leave you with the Seroquel and the Lamictal, and possibly the Thorazine. As far as neuroleptics go, I actually think Thorazine is a pretty good one, but shouldn't be used daily for prolonged periods of time. If you use the Thorazine as needed for anxiety/agitation, I think that is fine, so long as it isn't too frequent. If it works for you, try to reason with your doctor to keep a small PRN script. But, you need to find some cocktail of meds that will keep you well most of the time, without the need for Thorazine as a PRN. Gabapentin and pregabalin are good suggestions, though don't know how they would interact with Lamictal. They are touted to be good anti-depressants and anti-anxiety drugs around BL, although I have never tried either one. Perhaps, also an anti-depressant. Although, they can trigger manic episodes, yes, they can help relieve depression and help with manic-depression, on the whole. Prozac is a nice long-acting SSRI with no ups and downs in effect, which is about as effective as other SSRI's. I wouldn't suggest an SNRI or anything inhibiting the uptake of norepinephrine. In fact, clonidine might help (lowers levels of norepinephrine), although I'd be concerned it would be too sedating in combination with the other drugs, and could lead to hypotension. Starting a small dose might be something to consider, though.