You totally gave him the impression you aren't into him. Nobody is so busy that they can't find time to respond to a text message. He has backed off because of this.
General rule of thumb if you're interested is to say "I can't make the date you suggested, but I'm free on X and Y. How does that work for you?" From what you write, all you offered were apologies and excuses but you didn't make suggestions for a future date.
If you want to date him, you must now take the lead and prove that you are interested. If something comes up which prevents you going on another date with him, then just give up. We all know that if someone wants to date us, they will make time.
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.