[K. in Cleveland]

Wow, I can really see a lot of emotions must be flying through your heart and mind right now. I know you feel like you're in love, but I don't feel that at 12 you really know that kind of love, gay or straight or whatever. I'm sure you have feelings, and I do believe that people know who they are from a very young age, as to sexual identity. But love is a different story. At 12 your emotions are changing, you have hormones raging, there is chemical attraction going on... but love requires really knowing a person, and talking with them, being with them. You are experiencing a hard crush in my opinion. It feels like love, it really does, but it is not.
As far as this older boy goes... well, I'm not one to diss age differences, but at your age I think this age difference is a bigger deal. Your interests and his are most likely very different.
Also, do you know if this boy is gay? If he is not, and you do say something to him, he might say something mean to you and harass you, and tell other people who would do the same.
I know it's hard to ignore these feelings, but I feel at this point that is the best thing you can do.