I miss him as my friend. Things couldn't work out between us but I wish I could talk casually with him like he originally said we could. But I guess he decided he wasn't okay with that. 😢
It's hard to go back to being friends.. even harder if he still has feelings or didn't get over the relationship/breakup yet. Maybe one day in the distant future you might end up as friends.. maybe not..
Try to keep yourself busy, that way you won't have time to think about him as much and then regret messaging him. I think you need time to get over this, its normal to miss him, maybe now is not the time to be friends, its not a nice feeling though.