My horse rears when I tie him up, or when his lead is pulled?

How can I get him to stop? It has already caused injury to my boyfriend, who was holding the lead while he reared, and got rope burned hand really badly. I know to some it may not seem like a really bad injury, but I am afraid that next time will be worse. If you pull on his lead line hard enough, and when he doesn't go forward. As in, he doesn't like to leave his stall when there is food, so he starts pulling back and putting his weight in his hind legs, threatening to rear. Which in this case is extremely dangerous because he can hit his head. The other thing is that if he is tied, or feels tied, he will rear, and when he does rear, he goes all the way up. This scares and frustrates me, because now, when I NEED to tie him, he won't be tied. Also, I might as well ad in he doesn't rear when I'm in the saddle, but when I do ride him, he will buck at the canter, any methods to fixing that? I really don't want to have to sell him, because I feel like sometimes I can't handle him. Please help, and thanks guys.