My best friend has cut me out of his life, and I am heartbroken because I think this is more about a misunderstanding than any real grievance on his part. I know I didn’t help things by arguing about it, but I was angry at the time and felt as if he would change his mind after calming down. It has been a few months since we stopped speaking, and I think the opposite has happened. He no longer thinks of me or acknowledges that I was important in his life. The longer we stay apart, the easier I think it is for him to move on without me. I want him back in my life but don’t know what to say or do to convince him. How do I get my friend back?
You have to send him a message about how you feel and hope for the best. Yes, time apart may not have the effect you hope for, but this is ultimately about him arriving at an understanding of what you mean to him. If he doesn’t see that, nothing you say will make a difference. Try writing down what you feel, explain where you’re coming from, and tell him about his importance in your own life. If that isn’t reciprocated, you may have got this friendship all wrong and should reconsider it. You can’t force anyone to be in your life because those friendships, like any relationship, aren’t genuine and won’t last long.

I dated someone for a month until he abruptly changed his mind about going out with me. I have no idea what went wrong. How do I find out?
You can’t if there are no open lines of communication. It may have nothing to do with you and everything to do with his inability to articulate what is going on. Don’t be hard on yourself if someone doesn’t have the decency of being honest with you. If he doesn’t reach out, accept that this has no future and try moving on.