When I updated my game, I noticed a large fps drops as well, but once I backed up all my saves and then deleted everything in the .minecraft and redownloaded a fresh minecraft, it ran a lot faster. Try backing up important saves then deleting everything. I always back up my saves before updates anyway, so start doing that as well.
Hmm... It keeps telling me I have the latest version.
That is a server issue most likely. Try doing the same in vanilla LAN or vanilla servers.