this is related to masturbation but I really need some advice.

I'm 16 and I have been gay for as long as I can remember and now I really wanna just come out to people. I've only ever told 4 people and 3 of them were girls I've dated. I currently have a boyfriend and I feel so bad for not telling him the truth. I also have a big fat crush on one of my friends who my cousin thinks is into me but we have such a good relationship... I don't wanna risk anything by telling her I like her... what should I do?