What I thought was a best friend for life is no longer with me, and I'm learning how to live without them

(I'm male for reference.) I met the friend of mine who will be named Jayden online, while helping a friend of mine with a crush. she liked Jayden so I did some undercover work and got the two together, I was around sometimes so we were kind of friend of a friend, we even learned we had some common interests in games that we started to play together, they broke up but I stayed good friends with him and we've been playing stuff together for almost 3 years now, helping each other through personal struggles, dating advice, etc. then randomly about a month ago he starts being randomly cold from time to time, we get in some fights about it but make up. Until eventually he's just a straight asshole to me all the time and tries to say it's "jokes". so we get into it when he tells me I'm just corny and annoying. I finally decided that with this among other things that it's unrepairable and I tell him I don't wanna see him or any of the guys we were mutual with again and went on my own. It's currently 3 days after I broke things off with him and everything feels boring and like an empty shell of a full life, a lot of hobbies lost meaning and I feel constant boredom, really sucks that everything good must come to an end.