How do you train a mean iguana?

okay ive had my iguana for a year now anmd i still cant train him. ever time i try to go near him he starts to try to bite me or whips me with his tail and it really hurts. it makes it hard to feed and change its water. but he looks very lonely and sick right now. on one of his back legs there is like a big brown rough bump. i have no idea what toi do.