What do I do if my best friend/favorite person blocked me on everything?

That does sound really difficult.  When someone is important to us and there is a disagreement or argument, we can want to make it right as quickly as possible in order to repair the relationship.  Sometimes, that works and that's what the other person wants as well.  In some situations, it may be that the person needs some space or time for themselves to work through some of the emotions and thoughts that they're having over the situation.  It's hard to really say what the best approach would be to start a conversation with them but it sounds like the argument started over something that wasn't that big of a deal and escalated.  The only way to really be able to resolve the issue is to open a dialogue and reconnect, but I think it's important to give him the time to be able to process through some of these things that they're going through.  This can be really difficult and does require a great deal of patience especially during a time when we don't want to be patient and want to repair the relationship.  While we can't do anything about when he does or doesn't unblock you, we can do some things to help you process through this difficult time.  

One thing that we can do is reach out to someone that would be a positive support and share our feelings with them.  This can help you to work through some of these feelings and frustrations and give you a safe outlet to explore what happened and how you would like to work through it for yourself.  This can be anyone that is someone that you can feel safe with, whether it's another friend, a family member, or a counselor.  If those are not options that are immediately available to you, you could try journaling and writing out your thoughts and feelings.  When we are journaling, we have to slow down our thoughts because we can't write as quickly as we can think.  This helps us to think things through a little better and be able to see and understand things that maybe we missed before.

Another thing that we can do to help ease some of the anxiety that we're feeling is to practice regulating our breathing.  One exercise is called 'square breathing'.  Basically, it's controlling our breathing to slow down our heart rate and reduce the feelings of anxiety and panic.  To do it, you start by breathing very deeply for five seconds.  Hold your breath for five seconds.  Exhale deeply for five seconds.  Hold your breath for five seconds.  And repeat.  This can help because it slows down our physiological symptoms of our anxiety which helps to communicate to our brains that we're safe.