I can't make you not feel guilty or ashamed but I can tell you that touching yourself in a way that brings big pleasure is about as natural and normal as it gets. It doesn't make god kill baby kittens, it doesn't make your face break out, and it doesn't make you gain weight. It doesn't cause any harm to anyone. What is there to feel bad about? I don't know how to tell you to intellectualize this information but that's pretty much what you need to do... it's about the only way to stop the guilt feelings.