Well I tried Prozac last year and it only had a limited effect even after the doctor doubled the dose. I felt slightly happy a few times, but on the whole, I don't think it addressed SP for me.
I'm currently on Citalopram and the effects are more noticeable- I find myself a bit more outgoing and chatty, but I still have the same degree of SP. Side effects- felt tired all the time after starting it, but that soon faded away.
I'm going to go back to the doctors to see what else they can offer. He did say that it maybe the case of finding the right medicine that works for me.
If you decide to go, good luck! A visit to the doctors is definitely recommended.