Approaching the guy I'm interested in...

A couple of months ago, I met someone online, we talked a bunch and shared pretty personal and emotional stuff back and forth.

After a couple weeks of getting to know each other and expressing pretty explicitly we were into each other, we talked about meeting up.

Long story short, after a couple of hiccups, we met and talked for hours and listened to music. So far so good.

But in the time following I wasn't doing so well, dealing with depression and all that fun stuff. Between saying we'd meet up again but not showing up and deleting his (and most other people's) contact info in an emotional state, I feel like I've treated him pretty badly.

Since I didn't have his contact info anymore, I couldn't get in touch to say sorry or anything. Untill today I saw him online again, on the app I first met him. I want to talk to him again, but don't know how and what to say.