showing Mommy he's a big boy

Harry is growing up so fast and i don't like it. I've been struggling with what to feed him because one day he likes something and then the next he wont touch it. For instance, when ever i cut up grapes for him he puts it in his mouth and then spits it out but tonight after cutting one in half and spitting it out he helped himself to the ones mommy was eating and ate them whole. He didn't want mommy to cut them for him he wanted to do it himself. the little stinker ate probably 15 grapes because he got to pull them off the stem himself. It's like he's telling me he's a big boy and can do it all by himself. I am in the process of making a list of things he likes and will eat with no problem and the things he doesn't like and the last time i tried giving it to him. I want him to have a balanced diet but sometimes i feel like a bad mommy because all he will eat is junk or at least that's how it seems. hoping i'm not the only mommy who feels that way sometimes. sorry if i rambled but thanks if you read all the way through.