You may need another mood stabilizer. Lamictal (which you are not on much of at all) tends to help with depression a lot more than the ups. It is very effective for what it does, it just is limited with hypo/mania. And Wellbutrin is stimulating for a lot of people so you might need something to help balance that.

You really need to call your pdoc and to try (I know it is hard) to be really honest with your therapist. Tell them that you are having moments you feel suicidal; they need to know that. It doesn't mean you are going to automatically be sent to the hospital; a lot of people worry about that but it has to go beyond just thoughts before they can make you go. And telling them lets them help you. Tell them everything you wrote here, even print it out and let them read it. The only way they can really help is if you tell them everything.