Search Results: how to treat an ex

So me and my ex boyfriend have been seperated for a little over a year now (about 15 months). I always find myself thinking about him and missing him, but I know he'll never want to get back with me after the way I've treated him. But for some reason, I always find myself crushing on only his friends. I don't know if my mind does this because I think they're just flat out attractive, or if mind is doing this because it thinks somehow, this'll cause me and my ex to get closer again. And it's not like we haven't seen each other at all within that 15 months, we just haven't talked that much ever since. We pass each other through the halls when we walk from class to class, and sometimes give each other really awkward eye contact. But anyways, I'm actually really close friends with one of his close friends and it gets really awkward when our friend tries to spend an equal amount of time with both of us. Currently, I have a HUGE crush on one of my ex's friends. When I first started crushing on him, I didn't even realize he was one of my ex's friends (Btw, my crush and my ex aren't really close friends like me and the friend, but they still occasionally hang out together sometimes). Me and my crush hang out a lot and it's weird because when we hang out, my mind automatically thinks "Will 'my ex' notice me if me and 'my crush' hang out?" I have no idea why this happens. Am I that one over obsessed ex-girlfriend? Or what am I? I am sooooo confused. Someone please help me. I'll really appreciate it. Thank you!

Me and my ex boyfriend broke up over an argument a week ago (mainly caused from my trust issues)
Most of our fights is because of my lack of trust for him
He has never cheated on me before but I kept thinking he will cheat like my previous ex did but I realize now that I'm an idiot for not trusting him :(
I have told all my close friends about everything thats happened and also the things during the relationship (the good and the bad)
They all think he's a great guy (some of them have seen him already) as they know he treats me right and all that and thinks my boyfriend truly loves me
My ex even told my friend's boyfriend that I'm the best girlfriend he has ever had
All of my friends think he's going to come back even though he has blocked me from everything and deleted all our pictures straight away
They think it was the heat of the moment and he's not thinking straight at the moment and still angry and need space and that when he calms down, he will come back and talk to me
Then I asked my big brother for advice (my ex is 27 and my bro is 29) so similar age and my bro has met him before
My big brother thinks he's a great guy as well
I told my big brother what happened and all the things my ex boyfriend had done for me and all that
He told me that my ex is sick of my trust issues and that I should be the one apologizing and try messaging him again to see if he replies or not
But he thinks that my ex might not come back
Which one should I believe?
My friends or my big brother?
Im so confused