What do you mean turn your feelings into happy ones?
Are you asking how to prevent your feelings from making you feel upset, frustrated and ashamed?
There are a few good ways to do this.
One is to have a friendship with a boy. As far as I know, THAT is still legal. Just enjoy how silly, funny and loving they can be.
You must also accept the fact that you have these feelings and that doesn't make you a bad person. In my opinion it makes you a great person, better than average, but I'm a little biased.
Another good way is to have someone to talk to about your feelings who you can trust. This site is a great way but I know that many times I long to talk to someone in person. Try to test the waters a little and if you don't have the resources to find a really good therapist, try and analyze whether anyone you know will be willing and objective enough to discuss this with you. But be careful, many people will not react pleasently so please be certain it is someone you trust. I would not recommend talking to your parents even if you feel extremely close to them. They tend to let emotions get in the way of what you really need which is just a really understanding listener. Good Luck!