What do you do?

What do you do when you get into an argument with someone you care about and they stop talking to you? Do you give them a few days to calm down and then reach out to them or do you wait for them to reach out to you? I’m feeling a little indecisive because it’s been two days since our argument and we haven’t talked at all and I really want to message him to see what’s going on. I really don’t want to lose him, he means a lot to me and we’ve grown really close but I also don’t want to seem like I’m bothering him. We used to talk everyday, all day long and now we have had no communication in 2 days so I’m really feeling sad. I just want to talk to him to know what steps I should take next. If he doesn’t want to talk to me anymore then that will be his choice but his silence is KILLING me. I need to know something.. please send advice below.