Best friend is mad because I didn’t tell him I was dating someone

This guy has liked me since we were kids. I gave him a chance but I broke up with him because I wasn’t ready to be in a relationship. About 4-5 months later, I’m now dating someone & he’s mad that I didn’t tell him I was talking to someone “out of respect” of what we had. He said that he’s always there for me when I needed to laugh or vent (which is true). That I’m selfish, stubborn & inconsiderate (he said cause I always tell him what’s wrong but he never gets to tell me about his life). But that’s because I honestly talk SO much & I figured if he there’s something wrong with his life, he’d tell me to listen because he has something important to say. Am I wrong? Is he entitled to information about MY dating life just because he’s been there & I broke his heart? I feel bad.

Update: I don’t use him for emotional support. I only vent to him when I really can’t take things anymore (as in something really bad happened). & no, I don’t really offer the same back because when I want to vent, I just go ahead & do it. He doesn’t have to ask so I figured he has that same privilege & he’ll use it when he wants to.