After my surgery I finally felt well enough to take up a martial art, and I worked up to black belt and now I teach Japanese Ju-Jitsu. We don’t train by “fighting,” though, so I’m not sure it’s comparable to what you’d like to do. I’m guessing you mean Brazilian Jiu-Jitsu, right? If you wait until you’re fully healed and pay attention to your body in an intelligent way (and you train with decent people in a good dojo) then you can likely resume training. If you want to be an MMA fighter then I have no advice for you.