Does he like me?

So I was on tinder last week and I matched with this guy that I used to go to school with who I wouldn’t count as a friend, more of an acquaintance. Like we know each other well enough to have a conversation but I just haven’t had sufficient interaction with him to get to know him well. (he’s now at uni and I’m in my final year at school). I was going to message him but minutes later he unmatched me and I’ve been questioning why he did this. I’ve got a feeling he’s scared to approach a guy because he’s not out yet like myself but I feel like there’s something obvious I’m missing. Anyways I really want to make the first move and contact him in some way, but the only app I could do this on is Instagram and I feel like that’s a slightly weird app to approach someone on. At the same time I’m pretty nervous to approach him because I don’t know how he will react or if he’s even interested in me anymore. I feel like I need someone else’s perspective on this because at the moment I’m caught up in my own feelings.