What is going on?

For the past couple of weeks Ethan has been waking up earlier and earlier. He use to wake up at 7 everyday, which we loved! Then he started to wake up at 6, then it was 5, then it was 4 and ending with the earliest which is now 3. After an hour of trying to calm him down to go back to sleep, I eventually give up and hand him a bottle. Once he is done he goes back into his crib and I can hear him playing for about 10 mnutes and then he is out till about 7. I just don't understand what went wrong. He was doing so good, now it seems were are moving backwords. All the books say that he is going trough the whole seperation anxiety phase, but I don't think that is it because he could care less if I was in the room, he just wants his bottle. It could be seperation anxiety from the bottle, I suppose. I have tried packing his last bottle with cereal but that didn't work. Uugh I hope he either grows out of it or we are going to have to start reading more on how to solve our little problem. Any suggestions would sure be helpful.