What are you taking the Wellbutrin for? Is it for anxiety? Depression? or both?
If it is working...what is your main reason for wanting to stop taking this medication?
The thing is...there really is no herbal/supplement equivalent to Wellbutrin. There are supplements which may help to decrease anxiety and improve mood...somewhat but they may not be as effective for everyone.
I am taking a supplement called SAM-e and this helps with my mood greatly but...it is not comparible to Wellbutrin.
I would discuss your concerns with your doctor and see what solution you can jointly come up with. Whatever you do, don't go cold turkey on your medication as there can be adverse side effects.
Let us know what you decide to do. I hope you find something which works for you.