Most Helpful Guy
Sometimes the best way to defuse an argument is give both partners space and time to process the situation so emotions don't conflict with resolving this problem together. Misunderstandings, poor planning and/or laziness can get the best of couples sometimes and it's important to realize that it's not about who wins the argument, who was right/wrong but how well you two can manage after disagreements happen. He still loves you no doubt but is still frustrated with how much pressure you gave him when he couldn't make it to see you at the time. Give him some time to cool off but don't wait too long since that would give him too much control over the situation. Just be supportive and let him know you're available to talk when he's ready!
Most Helpful Girl
Seems like he's pretty much just temporarily hurt and needs time to process the argument. He's obviously got a lot going on so ease up on the poor guy!