Have you tried talking to them about your issues with them? I would at least recommend trying to resolve your issues first. It's ok if you don't want to, as you get older you out grow some friends and you will find your circle of friends don't stay the same forever. In the last 10 years (now 33) I have had 3 groups of friends all change. For 1, people grow apart and another, people move away.

One thing though, maybe you should speak to a professional about your sudden change and dropping friends straight after your new meds? Maybe they are having a negative effect? I am no doctor so of course speak to an actual doctor for clarification!

Aslong as it has nothing to do with the meds, it's ok, you will make new friends...even if it takes a while, you will meet new ppl...when you are ready of course. But then you have to find a way to meet new people. Or are there old friends you could reconnect with? Or maybe improve the quality of the friendships you have with friends you still have?