advice !

So, im 15 and i’ve been with my boyfriend (16) on and off for 2 years. i recently was admitted into a mental hospital due to my depression and suicidal thoughts and behavior. so the whole time i was in there my boyfriend has been there for me , calling me, checking up on me, and i bragged about him so much to my family that they actually like him for once. lately he’s been working hard to get money to buy me birthday presents and he’s so excited about it and then there’s this girl, she’s everything. she’s sweet, kind, funny, she gets me, she makes me feel good about myself but the thing is, i’ve never been with a girl but i can’t stop imagining what it would feel like to be loved by her mentally and physically. but then there’s a part of me that’s like what if i cut all these ties with my boyfriend and she ends up hurting me, i’ll feel lost and dumb. then there’s another thing, my parents don’t even know that i like girl also, i tried telling my mom a year ago and she was all like “are you sure you like girls? do you know what girls do?” so i just told her that i don’t out of fear and embarrassment. someone please give me some advice !! 😫