I was on Bactrim for a few months and it messed with my liver so they changed me to something called Wellvone which does the same job with no liver damage. I'm a high risk for Pneumocystis too. I'm assuming that's what PCP means??
I had it when I was in hospital for my stem cell transplant and it was really not nice. The doc didn't realise what it was so after two weeks of hell they sent me to have a lung sample....also hell

Now I take Wellvone twice a day to prevent it happening again. Maybe ask your doc about it....but geez is it expensive.
Anyway, hope you feel better soon