Actually i wanna vent about smth idk how to deal with this pls

Okok i have a friend who suicided weeks ago and she didn't live and i don't know how to deal with it. I miss her so much and love her alot, she was the most prettiest gi in school and everyone keeps wondering why she wanted to die. We're all about to gruduate highschool in a few months and I wanna know too... we both were going to be psychology students and she seemed so happy and i hadn't noticed a single thing about her. Infact she was with me the day she did it and we just were laughing. I haven't stopped crying ever since i found out she was gone. I literally still have her notebook with me i borrowed for notes. I don't know why she did it and then recently-

I had another friend who tried just over a week ago now. I was super mad at him and cried so much because we just lost our friend due to this thing and we his friends was so mad to the point we tried to find the source on why he tried to do it. I fear so much of losing him because online stuff has been impacting him way too negatively like he cares too much about some stupid likes or validation. I was so mad i didn't want to face him again then i heard he was trying to do it again. I don't know how to deal with all of this emotionally. I've been making sure he feels loved and everything but he's way too misreable just one negative opinions coming from friends and next thing you know he's hanging himself as if anytime he finds a reason he does it. I just wanna prevent him from doing it again and it's so emotionally draining but I don't want to lose him too not after i lost my bestfriend from it. Hardest part is I don't even know why she did it like no notes and shit unlike He, he leaves notes for his friends to get closure and that hurts even more! If you loved us so much why would you do such a stupid thing?! I'm so hurt by all of this. I know its harder for him but I just wish he would stop caring too much sometimes and he's awfully quiet these days i keep asking how is he how is he, nothing is said but i see his face fucking crying. I don't know if i should ask why he actually did it and what was his reasons cus "oh i made some people upset" isn't going to cut it. I know there's a deeper reason but he says "I'll be fine im trying to be a better person" and bs again because I know what this is, don't think i haven't been through with another friend like that before been like that with HER. She said things were getting better and she was all happy then i just find out she died? What if it happrns with him? it