Hi Garnetfire, Welcome to healing well forum, we are happy to have you join us. There are many antidepressants when you first begin them that will leave a bitter taste in your mouth. A little trick is to drink some orange juice and that usually will help get rid of the taste. Also, once the medication has started to reach its working level in your system in your body this normally will go away. So, you may want to hang in there and wait it out...see what happens as Wellbutrin XL is a very good and effective medication with one of the least side effects on the market today.
As for the weight gain issue it is difficult to tell if you will gain weight on this med or not as everyone is differant and reacts differant to these medications. It all depends on body chemicals and how your own body breaks them down. I used to have an artical on my PC regarding this but I have had my computer upgraded since and lost it. Let me see if I can find that again and post it.
I am sure that other members will post to you regarding this also. I do hope you continue to use HW as a resource and visit often, there are so many great people who post here who are always willing to help. Take care