I experienced the same thing with the PB shakes while doing a parasite cleanse - Projectile vomit as soon as i took it in!!...the only different is that i took garlic, while you're taking MSM.
Both of those are sulfur foods - which i subsequently found out i have a extra fast transulfation pathway and now have cut-out sulfur foods and am not feeling the daily nausea i once was.
So perhaps try to cut out the MSM...have a couple of days off the PB, let things settle down, and try the PB shakes again?