I would definitely suggest having your thyroid checked. In my experience, even IF you have all the symptoms of hypothyroidism unless your TSH is off the charts, they will not help you. I was on 10mg/ed of Sarafem for PMS (same as prozac really) and I quit taking it because I thought maybe it was prohibiting me from reaching my goals. As far as Paxil is concerned, as a woman, I would NEVER take that drug. It is notorious for causing weight gain so in case you are an "easy gainer" i would take that in mind. Wellbutrin is the opposite -- notorious for weight loss in patients who take it.
Overall, st johns wort is cost effective, no sides that I know of, and it does help.
Good luck!
Winners never quit...Quitters never win!!!