Should i try to get my ex back if he is willing to change?

You already said you were straight with why you dumped him. Guys don't really care for the explanation as much as girls do . . . it either works or it doesn't. Period. If you broke up on good terms all the better. Why are you expecting this guy NOW to change to make a relationship better for you? You got to take them as they are, they can only fake change for so long before the best of them takes over and their true colors show thru. If he is not the guy you would date as is, sorry, you can not take him to a tailor and have him altered.