I just realized I have been abused for years?

You should first ask him to take counselling , you never know what is the underlying cause of his actions. You have to leave of course as there is still a chance things could get worst. You must let him know that you won't come back unless he seeks help and you see and improvement in him, and not just by what he says you have to trust your intuition and know whether or not he's telling he truth because only you know your husband and can tell if he's being truthful or not. You must also attend counselling with him so that you two can figure out the problem together and to give you a clear idea as to what his thoughts and problems are.

"I just realized I have been abused for years" - your own sentence answers your question. If you are abused, you leave not to be more abused. It's a vicious cycle, and for the life of me I do not understand people who say that counseling can make your marriage strong, even after abuse. How can a person trust another who has pushed her against a wall or closet door, even after counseling? I couldn't. He is sending you a message - don't mess with me or it'll be worse. The threat is is implicit but the reality of the pushing and shoving is very substantial. The cycle: threaten/verbal abuse/physical abuse of any kind/emotional abuse - you are scared/hurt and he says it's your fault because you somehow provoked him - he then shows remorse, asks for forgiveness (not always, but sometimes) and it'll never happen again - short period of false peace - everything starts all over again.

Run, don't walk and don't look back.

They won't change. I was abused. I could have fought back, but I won't raise my hand to a woman. She started by throwing things at me (drinking glasses, plates, etc). She got so mad one time she punched a mirror, broke it, and I had to take her to the hospital to get stitches. Then, she began to slap me - that turned into closed fist punching.

Definately

YYYYEEEEEEESSS its time to go. Be aware that you should never let him know that you are leaving as that is what most sparks lethal behaviour in abusers, do not tell him to change either as he will eitherdeny his ababuse, blame it on you are agree to change and go back sooner or later. Look up "how to leave an abusive relationship" on google. Lastly when you leave dont let him know where you are and dont contsct him because he will either find you and kill you or he will promise to change only to becime abusive agsin after you fome back to him. You may not belive he will kill you becuase he has never hurt you badly, so did my aunt believe til the day she found herself driving 150mph trying to get away from abuive man who wanted to kill her after she left.

Sometimes violence within a marriage escalates from a push/shove to a punch real fast

Follow your heart. Many people forget that the remedies to their issues are usually inside them.

The longer you wait to end it, the more you will regret not breaking it off sooner

Usually it gets worse, not better.

Divorce him.