In my opinion, the best options for you are the binding and protection spells to protect you from possible negative or bad energies and to just not let your friends (or that person who discovered it) to tell that secret to everyone else (if they want to do so). So, try looking at Spiritual spells in the Spells section (obviously)! You will find them.
Well, also, I have a question, and I think it is a quite important one. You've said your friends discovered your secret and they might wanted to tell it to everyone else, right? But, isn't it true that real friends only want the best for yourself? That they don't want to make you hurt or cause you any harm? Then, why do they want to do that? What do you think?
Anyway, I hope this helped you.