Case of the ex.

Ok so like I kinda want to know where this dudes head space is when it comes around to me Bc I’m currently hurt,horny and lonely I’m pretty sure he cheated on me with my “bestfriend.” I have no solid evidence , besides from suspicious behavior from both of them , Bc like he claimed he was having “family issues.” like now that I’m looking at it from a higher perspective Ik every guy copes differently usually he would tell me and he started acting suspicious like hanging up on me not calling back etc etc there’s more so much, Ik I’m dumb how do I construct an essay trying to get him back? let me explain idk why I even want him back it’s jus I felt so comfortable around him hes such a good gaslighter , he’s not abusive or mean , I kinda want revenge and I want to know why he did what he did he won’t even admit it my thing is how come they get to be happy , like wth? what did I do to deserve this ?