feline hyperesthesia

Hey guys, So Oli (1 year old sphynx) has been doing these weird twitching freak outs recently and the skin on his back starts rolling and he runs around like crazy. I looked this up and it is apparently Feline Hyperesthesia. Ever since he was a kitten, he always licks and chews his tail a lot...

My little Swindle (6 year old male sphynx) recently had bitten his tail to the point it had to be amputated. About 2 inches from the tip. He use to just lick it. We are going through various steps to try to fix it. As he is in a cone now. It is healed but he continues to try to bite it. I have...