Reading gay angst is actually harmful guys

I forgot the title of this but I think it's similar to "When haru was there"? Idk anyways basically this guy keeps texting this number which belonged to his dead bf but now someone has it and they been reading those text and idk I think they got together I never finished it and forgot the title and btw I read when I was grieving over mine too so I cried and got an idea from the book and uhhh my unhealthy coping mechanism started there, harmful cus I was in denial lmao but also aye I need the title of this series