How do I get along with my stepmother?

The relationship between my stepmother and I is a little unusual. When I first met her, she was practically God to me. She was probably the coolest adult you could ever meet. We would dance around the room together, shove giant wads of gum in our mouths, and laugh hysterically my mother (which I now realize was wrong). She had a million animals, and was extremely kind and loving. We had a fall-out in the two year period of our relationship. The whole thing was definitely my complete fault. I would hang on her and would never let go one minute and completely ignore her another. She wanted to leave because she couldn’t stand me and I understood. But of course she didn’t, I guess I just resented her being around my dad constantly, she could do no wrong and that’s something that I resented as well. After the huge fight, I think it’s been three years since, I made every attempt to contain myself and be nice again (I sound like a witch don’t I?) things went back to normal for a while and then it stirred up again. She wouldn’t let me help with the horses (I always did) and she wasn’t as happy as she used to be. She didn’t wrap me in her arms and call me her baby anymore, she didn’t look ecstatic when I came home from my mothers, she didn’t bring me little surprises (like a piece of candy she found in her purse) I missed that. I thought it was because I’m getting older but I’ve realized that this is something that stepmothers all do at one point or another… overindulging their stepchildren to get them to like them. It wasn’t the dwindling of a flame and just getting used to each other, the way she acted before just stopped. She wasn’t the little kid who would cuddle up to me and watch Sponge bob anymore. So now that I’m much older, I don’t want that, I want to spend a little time with her (because I know she’s very busy),I want to be comfortable around her again. I feel like such an idiot because I’m the one who’s trying to win her affection, and bending over backwards for her so she’ll like me. Isn’t it supposed to be the opposite? I try so hard to look incredibly happy when I see her but she just says “hi” in a very monotone voice and hugs me. Am I asking too much? What can I do to make me feel comfortable around her again? I know I should talk to her, but she makes me feel so helpless. HELP!