What Just Happened? (IR 10 - #2, April 6 - Undated)

I'm extremely confused about the last part of the book. I understood everything that went on until Alice ends up in the hospital. I really don't get what happened. She was doing really well at home and everything and she really started to like herself more and she no longer hated everything that she was and everything she has done. The kids at school were harassing her because they want her to do drugs with them again. They keep putting blunts in her bag and in her locker so she continues to get in trouble but her parents believe her. They know that she's getting taken advantage of and bullied in school. So Alice seems to be doing fine, but the n she doesn't write for a while and there are undated posts after that. Apparently, someone put acid on the peanuts that she was eating while she was babysitting? I'm pretty much really confused because I have no idea how the acid would have gotten there. It honestly doesn't make very much sense to me at this point. It was really confusing to me hearing about her trip. Actually, it was more scary then confusing. She literally freaked out and started clawing herself everywhere because she thought that warms were eating her alive. The acid trip lasts for a really long time even when she's in the hospital. She continues to claw herself and hurt herself and pull out her hair. She can't remember exactly what happened while she as babysitting but apparently she locked herself in a closet because she thought she was going to hurt the baby? I'm just very confused by the whole thing because I don't get how someone else could have given her the drugs. Maybe she's lying? But she's also not the one telling people that, her father is. She thinks she knows who the person is but she is to afraid to say. At this point I'm just extremely confused. I wish I could piece together everything that happened because I would really like to understand it. In the end, Alice ends up ok and starts making new friends but then in the epilogue it says that she dies from an overdose 3 weeks later. They don't know if it was accidental or on purpose. I kind of wish Alice wrote more in her diary so everyone could understand. I'm left kind of confused and wondering what happened.