Said they’re not ready and stopped replying, I was totally blindsided

I (26F) was seeing someone (31M) for 6 weeks, we went on a few dates, they were very forward and enthusiastic, texting daily, alluding to future plans/dates, wanting to meet my mom, etc. Afaik we were both only talking to each other at the time. We both hit it off really well, but a couple days after our last date they stopped replying to my texts, and a day after I asked if everything is okay, they said they realized they’re not ready to be a partner, said I did nothing wrong and that I was kind, honest and respectful, and said they’re sorry they can’t do this. It was a pretty short message. I asked if we could stay in contact, said I’m keeping my door open for them if they want to reconnect, and that I really could see myself being serious with them. They haven’t replied.

They got out of an engagement in April they mentioned messed them up badly, and I noticed their apartment seemed kind of barren/not super put together as if they hadn’t adjusted everything after the ex fiancee moved out. Bc of this I want to believe them, but their sudden lack of response after being so communicative scares me. I know I shouldn’t text them again, it’ll probably just make me look pitiful. We never had sex, although we wanted to, they wanted to wait until we were closer. I did go down on them on the last date, which they seemed enthusiastic about, but I don’t think they wanted to just use me. They’ve stayed matched with me on the app we met on, and I can see they’ve been online on it last a checked (a few days ago), and haven’t blocked/removed me on the couple other platforms we were friends on.

I’m trying to move on and if they’re on my mind in a few months maybe I’ll ask how they are then, once I’m healed, but right now feels suffocating being in the dark like this. I’m trying to stay no contact, but I was so blindsided and was catching feelings, this came out of nowhere only a couple days after they invited me on a couple dates that coming week, and a concert a couple more after that. I know speculation is useless, but I guess I’m just hoping for some kind of thoughts/opinions/input on the situation? I’m trying to be positive about it all, but not delusional while allowing myself to keep growing myself.