Emotional rollercoaster of a love triangle results in heartbreak and relationship exploration for the main character

[Gabriela]

From what I remember, the main character is in a bit of a love triangle. She has family friends that she has been close with forever and they feel like family. Her best friend is the younger brother but she has always been "attracted to" or "interested in" the older brother (i think). She used to talk to their mom about everything because she couldn't talk to hers (her mother was mentally i'll and spent a lot of time in bed). When she finds out the family friends mom is sick, her life flips upside down. Her best friend (who was secretly in love with her even though she had something with his older brother) is an emotional wreck and dies in a car crash which completely ruins the dynamic the main character has with the older brother. They have "sexually" relapses and continue to explore one another but the heartbreak of her best friend being dead and his mom dying (dies) makes the story an emotional rollercoaster for readers.
I read this book in March of 2021 and I believe it was new at this time. No promises though.
I really want to reread it because i remember it being phenomenal!
Thanks :)

[Lobstergirl, au gratin]

Gabriela, is this fiction or nonfiction? That needs to be in your topic header.

Additionally, this header is extremely vague - it could apply to many, many books, so we need you to put specific plot details in the topic field.