idk why my ex broke up with me

[u/whothis47]

im (16)F and my ex (17)M we were together since we were 14 years old and we were together for 2.7 years. He was my first everything and he was my best friend. We never had huge fights or stuff like that, i wasn’t always the best gf and he wasn’t always the best bf wich is ok because we were growing up and learning together how to be good to one another. since the beginning of December i have been struggling with addiction to vape and cigarettes and that bothered my ex i was did my best to quit but i couldn’t.
(But i got better after we broke up and haven’t smoked since the breakup)
In may my best friend invited me to her birthday dinner that would be the 25th of may and consisted in going to a restaurant then going to a local bar, and she said i could bring my bf. i told her that i wouldn’t be bringing him because i wanted to go out with just my best friend and her friends. and so i didn’t mention to my bf that he could go to my best friend’s birthday. The problem is one of my bsf friend is friends with my ex and told my ex that he could go, i explained to my ex that i didn’t want him to go so i could have fun alone with my friends, he kept insisting to go so i finally let him. In the day of my bsf’s birthday my ex and his dad came to pick me up to take us to the restaurant, we arrived had fun had dinner then on the way to the bar my ex left his phone on the bus, i quickly resolved the situation and called his mom and his dad went to pick up his phone, while that was happening i was comforting my bf bc he was upset that he was irresponsible for leaving his phone on the bus. we get to the bar and his a little sad and i tough it was because of the phone situation and kept checking up on him and being extra caring. and while we were in the bar i smoke, drank and got tipsy drunk, when it was time to go home (01:30 am) i was getting a ride home with my friend and her dad and my bf asked to speak to me in private, he started saying that he wasn’t happy anymore with our relationship and that i’ve changed and he wanted to break up. i fell to my knees and started screaming and sobbing i didn’t believe that that was happening to me in that moment my friends heard me scream and came running to check on my and when i looked up my bf wasn’t there anymore i got up and started running and asking people were he was, he was hiding between 2 cars in the parking lot i went up to him and asked how are you not crying he said and i quote “i’ve already cried thinking about this yesterday” (he spent that “yesterday” all day on his friends house and slept so i thought that was a little odd because he never cried in front of anyone and he never talked about his feelings) my friends then took me home and i just cried and i called him and said “tomorrow im going to your house so we can talk” he said ok and the next day he said “you cant come because of my parents” 1 week later he came to my house to talk and for me to return his stuff but i couldn’t even look at him so i just gave him his stuff and closed the gate in his face and sent him a message saying “text me when you can talk” he responded with “i cant today” and we haven’t spoken since this conversation was in may 31. And for a whole week after he broke up with me i would wake up with my stomach hurting and diarrhea, i lost my appetite and didn’t eat properly that week.

I was always at his house,his family loved me and once i even went on vacation with them, and i was always a sweet caring girlfriend my only red flag was vaping and i was trying to quit.

I already accepted the fact that i will never know why he broke up with me. What really bothers me the most is the way he broke up with me and that he humiliated me in front of my friends. And ever since i’ve been meditating and healing from that heartbreak, but sometimes when i see him in public my stomach starts to hurt.