I am sorry to hear your having such a problem. He certainly has your number and does not view you as his herd leader. I would definitely stay away from the treats, he needs to view you as the herd leader. Your horse is most likely fearful and anxious because he does not have a herd leader. He knows he can dominate you and does not see you as his leader who will keep him safe. Consistency is the key, you have to pick a method your going to use and stick with it. You have to be alpha and prove to your horse your worthy of being his leader, and that you have the ability to make him move his feet.
I am going to recommend a book Establishing Respect, by Clinton Anderson, it is easy to understand, Clinton is black and white no confusion in his teaching and methods and will help you gain your horses trust and respect. In the mean time carry a training stick with you at all times around your horse, if he comes into your space threatening you, or uninvited chase him out of your space and make him move. Alpha mare will bite, chase, kick do what needs to be done to move the herd, especially the disrespectful ones. Do not feel bad about whacking him if you have to, alpha mare does not feel bad when she kicks a herd mate. Show him you can make him move, yell, swing the whip, chase him; make him think your going to kill him. Then go back to what you were doing. If comes back in do it again, your going to have to get tough, or your going to get seriously injured. Two eyes are better then two feet, if he turns his butt to you whack him from a safe distance and move his feet. Act like an alpha horse would in the pasture, do not take his crap. He will come to respect you, and his fearfulness will go away when he knows someone is in charge. Good luck to you and be safe.