I'm sorry your daughter is having such a difficult time.  What does her doctor say about all this?  Wellbutrin is a good drug, but she might need something else for the irritability.  My son takes both Wellbutrin and Abilify - the latter was added because he was feeling angry all the time.  Is your daughter a minor?  Even if she isn't, you can call her doctor and tell him/her what's going on with her, without him having to divulge any confidential information to you.

I hope she finds something that will work well for her and I sympathize with what you're going through - I've been there.  Please let us know if we can help with anything further and keep us posted on how things are going.