You mention you are pretty distraught to the point of self harm. That needs to end. Go get some help for that. Nothing is worth hurting yourself over. Also coming out whether its bi or gay is one of the hardest and most emotional things a person can do in their lives. You do risk losing very important people, family and close friends. Is it better to be honest with yourself and others about who you are or keep it all in? I don't think you need to tell your bff you are in love with her and I can't tell you you need to come out to her. You already know what she has told you about how she feels but sometimes people surprise you. I guess I feel that you would feel better if you "came out".at least that part as far as the in love I would probably wait until she could digest the other information. I know it would be hard. I know you risk the chance of losing someone you care deeply for but right now you are holding it all in and hurting yourself physically and emotionally. That isn't right. Like I said you don't have to tell your deep emotions just tell her who you are. Anyway only you can decide what you want and are able to do. Good luck.