First let me welcome you to HealingWell and to our board. I hope you can find some helpful discussion here.
Sounds like you both are in a very difficult place right now, and I can tell you as a woman (regardless of the bipolar) that's where a lot of the libido problems are stemming from. Stress and uncertainty. She's probably not feeling attracted to ANYTHING right now, even you. I can't guess what she's thinking about your marriage in general, but I do think it's a good bet your own anxiety is magnifying her signals into signs of doom right now.
Committment issues can be problems for some bipolar people, usually when they're manic, but committment problems are usually associated more with Borderline Personality Disorder.
I think before you confront your wife on this again, talk to your own counselor. Get some guidance on how to proceed. The counselor can teach you some ways to phrase things and situations to proceed in to try and make your questions the least intrusive for your wife and the most helpful for you.
BTW: Abilify isn't usually a mood stabilizer -- it's an anti-psychotic (for mania). Does she have another drug too? I would take the chance and mention this to her, or again, wait and talk to the counselor first. Meds are important.
Co-Moderator, Bipolar Forum