I know this will sound unrelated, but trust me, it's not.

If you're free feeding switch to feeding him only two or three times a day. Make him sit and wait before his meals.

Even better, hand feed him. Make him wait a few seconds every now and then. Especially if he gets rough. When he takes gentle give him soft high pitched praise.

---

another thing to do is practice with something he is allowed to have.

Play with him and get him worked up. Hand it to him and say Yours. Take it away and say Mine. Say Yours and hand it back to him right away. Let him have it for a bit.

---

Have you tried yiping when he bites you?