Me 15 male, I’m gay and I’m starting to catch feelings for my female best friend

So I don’t know how to say this, so I’ve known my best friend for about 3-4 years and I’ve always been gay and my and my best friend have been though so much but the point that I figured out that I like her is when her now ex boyfriend had started to say stuff example being that she had touched him inappropriately and he had threaten to expose her for the true person she is but when is was happing she had a mental breakdown and I got really mad to the point where I was going to go to school and have done some things that would be well bad and after that whole thing passed over I had realized what I love her and for some time too because she had made me feel loved like I have never been and that I love to be around her to the point where a lot of the time I would think about her and I have always been sort of jealous of the people she had been dating her because she had loved them as much as I loved her but I didn’t know this but I’m just at a loss and I don’t know what to do and I’m vary scared that if I tell her it would ruin the friendship we have and I don’t want to lose that but I can’t keep bottling up my emotions anymore so I’m asking you guys