Advice please

me and my boyfriend have been together 3 years and we have a daughter together. He is the only person I’ve been with and he has a really large penis. at first i thought that I’ll get use to it but i just can’t be never sticks all of it in and i can never go that long during sex and it makes me feel like a little girl which is quite embarrassing being that im grown up. we started talking when i was 18 and we have a 5 year age gap. He never throws any of it in my face he just work with me but i sometimes feel bad because he has way more sex experience than me but he always tells me its not about the sex but i feel like i bore him and he says it’s not about the sex but like after like 3-5 minutes i feel like i can’t go anymore and when i nut i never notice then he’ll tell me like you know you nutted but i just wish i could do more and have a lot more knowledge i know it’s embarrassing