My bf Gets annoyed when I talk too much (f19), (m21)

Hi so I’m very confused on what to think and Need some opinions outside of my own.
I’ve been in a relationship with my bf (21) for slightly more than a year and despite our ups and downs

I’d say he’s a pretty great person and I really appreciate him and our relationship despite our differences.
He’s sincerely, very respectful, kind, we talk things out and he Tries to be there for me when I need it, I’d say I do the same for him.

However, One thing that bothers me and hurts me a bit everytime it happens is that every once in a while I might start talking about a given topic for a liiiitle longer than he’d like (context: because I know I can talk a lot when it comes to topics I like, I always ask him, or my friends in general, if I can go forward and talk about it) I don’t mind if the answer is “hey, maybe another time” at all, I understand one might be tired or not in the mood, of course. But it’s not the first time that I ask him if I can talk about something real quick (it happens once in a while, it’s not so frequent ,good 80% of times it’s ok when we talk) and he goes “sure” only for me to end it saying “hey sorry for that” (I’m still very insicure when opening up with people or talking more than two sentences) and him dismissing me like “oh yeah sure it was boring But dw”….

it makes me feel like I can’t express myself, kinda.

And also, when My friends or family members are talking too much I tell them kindly (worst case scenario that I’m very tired) that I’d rather be listening to them better another day… even then I would never want to make them feel like they are boring me .
Idk what to think. Am I being insecure? Is he being tactless? Is it my rejection sensitivity? Are we not compatibile? Any opinion is welcome, I need insights lol

Tl;dr : sometimes I feel rejected by my bf when opening up (after I ask him if he wants me to) and Idk what to tell him, or think.