I Dealt with this problem too. exactly the same. I brought it up to him, hard as it was cuz i'm not one to ask, then I kept telling him things he used to do to see if he would return to trying that way, finally I realized he didn't want to try so I broke up with him. It was hard, I Took it back the day after and then I told him it was over... It was good, I have a new boyfriend now and it's been almost a year and he's only treating me better now than when we started. I'll see if it continues. A relationship need two people trying, it's unfair for him to receive and not give no matter if u mind or not, it damages your spirit.
Nothing is as important in any relationship as communication. You have to sit down with him and tell him what you feel because to him, he might not have changed. It might be possible to go back to when you met, but I'm sure he can find some ways of spicing things up a bit.