Needing help ASAP, been asked to go climbing with the guy who made me realise I was a bit gay

Long story short: I've known this dude for a long time, dated for a day in year 6, and only recently started talking again after middle school.

He invited me to go climbing last week. I said I couldn't and put it off until this Saturday and invited another mate because lord am I nervous.

But he's texted me asking if I wanted to go today in 2 fucking hours. I haven't opened the message and there's a photo I can't see with it. What the fuck do I do?

I used 'shed renovation' as an excuse to put it off, until my other mate is free to be a buffer for my blatantly obvious unresolved feelings for this guy. Usually I can get by since i still don't know what type of gay i am, but this guy was the dude who made me realise i was somewhere in that ballpark to begin with. So even if it's just friendly now (especially since he might have a boyfriend) I can't take it.

I'm usually quite chill, but I don't know if I should even go since I have no clothes that don't look like shit and I'm barely awake right now. Also i'm shit at climbing, I just enjoy it. And I can't avoid him since I live right next to the fucking train station he gets off college from.

I need some help ASAP please.