We were friends for many months, they helped me through a toxic relationship and then we dated for just over a year. But we broke up because they couldn’t handle a relationship in college, no matter how willing I was. It’s been several months and it still stings every time I strike up a conversation only to be left on read after a few messages are exchanged. They did leave the possibility of getting back together, or doing something when they’re in town. 
No matter how much I analyze the situation I can’t find a reason to be upset, but I am incredibly distressed and I feel I will never come close to that good of a relationship again. 
Any advice?