I miss him (long post)

So I dated this guy for almost a year and we went through everything together and toward the middle if our relationship. I got kinda cheated on(he told a girl if he was single he would think about dating her) later on toward the end of our relationship we started to drift apart because of our lives and we broke up sooner later and now hes been gone for almost a month and we started talking again a couple weeks ago and everyone stressed me out so I dropped him and it was the worst decision of my life. No matter how he treated me I still want him back and I just recently got in a relationship and I dont feel anything with him and I cant get my ex out of my head I want him back so bad but everyone will hate me and I'll lose my best guy friend if I decide to text him. I really hurt him and I just want him back in my life. He makes me so happy no matter our lives and drama. Can anyone help me figure out what to do i really need someone rn.