Hate/love my ex. cant get back together, cant forget about him...?

The reality is there will always be sparks between you two but you must remember that he chose the other lady. He has made his choice so it's up to you to control yourself and your urge to be with him. Please don't do something dumb like start a love rivalry with the other girl because that just makes a guy arrogant and it goes no where. Do what you have to and get over it. He made his choice and it wasn't you. You guys can talk and get along, and hell, you can even imagine what life would be like if he had chosen you but he didn't and you need to remember that and move on.