In love with my best friend 😞

So I have recently gotten close to a guy I like in the past few months lets call him guy A. I first met him in 2018. I really just admired him from afar but never really talked to him. Early in 2019 I saw him again and talked to him a bit. I completely fell for him again. Now around this time, I had another friend, guy B, that I kinda liked but I kept going back to guy A however Guy A had a gf. I got rejected by Guy B and basically ruined my first semester of high school since he refused to be my friend. I kinda was just cruising, except when I tried to make a rebound that smacked me in the face. In the fall of 2019, I met Guy A’s gf. She seemed nice but just had the bitch look to her but I was crushed because they seemed so close. I later found out that he broke up with her like a few weeks later and was single. We started talking a LOT more. Now in this last month, we saw each other again. He completely opened up to me about his last relationship and how toxic it was. I hung out with him a lot that weekend and our friends starting raising eyebrows. Anyway, a few days ago my friend went out of her way and into my business and asked him if he liked me then more than just a friend. He told me about it and said he didn’t care. I just want to spill out my guts to him but I'm worried about when to do it and what his reaction is going to be. He has saved me from a really dark place and I can’t lose him. Idk what to do. I need help.