I’m sorry you had to go through this too, my friend. Unfortunately, it takes time to get over a bad relationship like thus one. To be fair, every broken relationship hurts, and we end up thinking about our exes for a while.
I don’t know if they are using us. Most likely they are. And even if they don’t realize it, it’s not an excuse. Everyone should hold themselves accountable for their actions. Partners who behave like that are simply selfish and self-centred. They only worry about their own feelings and emotions, not about other people. In my opinion, such individuals are unfit for relationships. I ran for the hills, and I’m glad you did the same thing. I sincerely hope you will meet someone decent.