In love with two people? SO confused, please help!?

Now, maybe I'm not in love, but I do have very strong feelings. I'm fifteen, and I have a boyfriend of two and a half months, my longest relationship. Before Heath, I was with Eric. He cheated on his girlfriend Kayla for me, and promised he'd end it with her soon to be with me. You're probably thinking "if he'll cheat on her, he'll cheat on you, too." We've had a long talk about that and he reminded me that I was the one he cheated on her for, and he's never cheated on anyone before or after that. We've been talking since then. We Skype every night and text all the time and say "I love you", which I kind of consider cheating. I love Heath, too. He's perfect- sweet, has never hurt me, loves me to death, and is very attractive. The problem is, I love them for completely different reasons. Ever since Eric and I started talking more recently I feel like I'm losing feelings for Heath. I can't see him with any other girl. Even the thought of it makes me feel physically sick. I can't stand hurting him like this. I told him about Eric and admitted to being completely confused, but he said he'd stay with me no matter what, he can't lose me. I'm seeing Eric for the first time since October this weekend, but we promised we wouldn't kiss or do anything along the lines of that, just talk. Please, please tell me what I should do.