am I that annoying?

Ok so every once in a while I meet a guy and we start texting each other, at first he will respond pretty quickly and I start feeling happy because I feel that he's taking the time to talk to me, but then as time goes on he takes longer and longer to reply and then he starts to rarely reply or reply with few words and sometimes he just doesn't open the chat to read the message so I won't know that he saw it. And finally I just stop messaging because he never messaged first and when I stop messaging we never really talk again unless it's in a group chat or something. I've been told I'm annoying many times and I've changed myself enough that instead of being super outgoing and being able to talk to anyone i just stay quiet and barely speak unless it's to my friends...