Guy trouble...Help

Okay, so I like a guy right and I know for a fact he likes me he often tells my best friend how he feels about me. We recently started texting and once we text we can't stop we'll just keep texting all night however recently he texted me at around 3 am and I was asleep so I did not see the message until the morning. I replied and he never replied back to me it has been to days and I'm getting anxious here. What do I do? I don't want to text him again because it's bad enough he didn't reply to the 2 previous messages I sent and i don't want to come off as desperate?! :(