Help - I can't tell if my ex is still interested in me.

Hi everyone, thanks for reading my post!

A little background about us:
We were together for three years. We had a very loving relationship and our personalities are compatible on a friendship level as well and a romantic level. He was my best friend. We had arguments like everyone else but most of the time things were great between us. It wasn't until the last few months of our relationship that we started to fight more seriously. He started to feel very depressed about aspects of his life (job, school, etc.) and he began to take it out on me. I tried to be there for him as best I could but he didn't improve, and the fighting continued.

Eventually we both got tired of the stress and we decided it might be best to separate. The break up was hard on both of us. We both cried and we kept going back and forth on our decision, but honestly the break up seemed like the right thing to do. I suggested that we take a few weeks apart and maybe we could talk after that, and he agreed. We hugged for a long time before he left and we left on good terms, with no ill will towards each other. We didn't speak/see each other for three weeks. During that time I thought a lot about us and decided that I'm willing to work on our issues so we can be together again, and be happy. He broke no contact and texted me today. He was very friendly and talkative. He asked me questions about my job and school, and life in general. It seemed like he really wanted to talk to me. He told me that there are so many things that remind him of me and that he thinks about me a lot. I was engaging but I tried not to seem too eager. I had to end the conversation early because I was going to the movies but before we said goodbye he said, "I want you to know that I miss you and that I really hope to hear from you soon."

It's probably just wishful thinking but part of me thinks he might still be open to the idea of us being together. But I know that just because he misses me doesn't mean he'd consider getting back together, which is why the other part of me thinks he's probably just trying to be friendly. I don't really know how to read the situation because we didn't get to talk for very long.

I also don't know how I should handle talking to him from here on out if he contacts me again, or if I should reach out to him in a couple days. I'm really lost at what to do. I really want him back, I don't want to make a dumb mistake and push him away.