First of all i can sympathize with you OP, because I have ADHD and generally find myself speaking before I think. just the other day i made a joke to my friend that came out the wrong way and i felt really shitty about it.

It sounds like you struck a soft spot, and perhaps your friend was already dealing with some internal emotional stuff at the moment. If you guys are good friends already, trust that one comment is not going to change that. Everyone slips up every now and then. Sounds like you had no malicious intent whatsoever.

Give him space for a few days and reach out to him to clear things up. In the meantime, do something to help yourself calm down. Don’t beat yourself up over something that already happened.