What to do now? Still no response.
You made two main mistakes:
You kept asking to meet on very short notice - the same day. He seems to be going through a busy period and probably can't be as spontaneous as you'd like like.
You kept telling him not to worry about not making the date. This may cause him to not respect your schedule.
I think he's still interested in you and will probably respond eventually. However, you need to let him re initiate and don't plan the date the same day next time.