Why is he a jerk and is it my fault?

You did the right thing. When you are ready for a relationship you would know it. But if he doesn't understand or gets upset then that's not the right guy for you. And he probably wanted some thing out of the relationship. In a relationship it's important to have, Respect, trust, communication, patience, honesty, kindness. If someone doesn't show or give you non of these then there's no way that the relationship will ever work. So just let him be. There are better guys out there that would understand what it means that you're not ready because so much is going on. Most guys don't understand and get mad. They don't understand it has nothing to do with them. It has to do with what you have to in life. And you didn't want to involve him in the middle of anything that may be happening good or bad. Be with a guy who will understand and also friends along the way.