Should I message him?

I have feelings for a guy (long distance), and things went downhill and he told me he doesn't know how he feels anymore (when originally he had feelings for me). He's super busy with work, which I understand. Yesterday, I made a stupid decision to hook up (only making out) with a guy, and I told him about it today because I felt really bad, to which he replied with 'oof fair cool'. I asked him if he was mad, he didn't say yes or no, he just said it happens and told me not to stress about it.

After, I said something (flirty) to him and he left me on read and hasn't texted me since (an hour ago, but he's been active). I feel like I've messed up, but he didn't tell me he was mad and also told me he didn't know how he felt. I feel like he is mad though, because he always replies, and always gives me something to reply to. Not just 'oof fair cool'. What do I do? Message him again? Give him space? I messed up because his birthday is on Friday, mine is on Saturday.