Ummm, yeah . . . the Wellbutrin may be having an effect on you. That was one of the drugs I tried in an effort to quit smoking, and I had to stop Wellbutrin within a few days because I felt kind of light-headed and slow . . . kind of like I was thinking through cotton. (Yeah, I know . . . doesn't make a whole lot of sense.)
Yes, cutting the eliquid will reduce the flavor, but some don't find it at all objectionable. Common "cutters" include vegetable glycerin or propylene glycol. Vegetable glycerin is generally the easiest to find--check out a craft store that carries stuff for baking/candy. Michaels generally carries Wilton's brand of glycerin. You can also find it at many drug stores, although not all are food grade.
To get around the taste issue, many people will add a bit of flavoring to the eliquid once it's been cut. Check out the DIY eliquid forum for TONS of information on that. Please do read up on it before you try to cut your liquid and/or add any flavorings, though, as there are some definite "dos" and "don'ts."
