Effects of Paxil

My question has a couple of parts. First of all I have been taking Paxil for almost 3 years now.  I take it along with Wellbutrin.  During that time I have noticed a change in my sexual function. When I am masturbating it takes more work to get aroused and ejaculate.  When I am having sex I never climax and my erection fades sometimes.  My question is, why can I ejaculate when I masturbate but not during sex.  Is this some weird dual side effect of the Paxil.  Also what is it about the psycological/physical effect of Paxil that affects sexual functioning.  Finally on a side note, is the problem that the women I am with are not that attractive (fat) and I am just not that turned on by them or is it the Paxil.  Also why when I smoke weed I can ejaculate and become much more sexually stimulated.  Thank you for taking the time to answer my question.
ERNIE

[Roger Gould, M.D.]

Paxil effects the brain chemistry that controls    ual function and that is why you are having these kind of problems. When you smoke weed you are effecting that same system in a different way.

[keano12]

I am in the same boat been taking Prozac for like 2 years. It has helped. But I notcie I find it hard ot ejqcualte during sex (I am married) when masterubating I do ejaculate but I notice doesn't seem as erect or turned on?