I had to become self employed to get away from that sort of shit. Bosses like the one you describe are insecure with their own abilities so they have this need to belittle the efforts of those they are responsible for, dont let them sense your vulnerabilities, dont rise to the baiting , just reflect on the fact that the problem lies with them.
Your boss sounds like a bully to me, that isnt a good management style imo. Good luck with dealing with this arsehole, treat him/her with the contempt they deserve.