As far as natural supplements that help with anxiety, I could tell you a few that are actually highly effective, non addictive natural supplements that help with anxiety/panic, but I'm telling you, you're going to get yourself into deeper shit by mixing GABA or 5-HTP in when you're already taking Wellbutrin. You're screwing around with your neurotransmitters and that can really make you nuts, literally.
No criticism or judgement, but be honest, are you playing pharmacist on yourself or is this monitored by a physician?