Someone plz help me😂🤦🏼‍♀️

So i got a boyfriend around the end of last year and we waiting awhile before really doing anything and when we started to he wanted me to give him head, i was completely up for it (i am his first girlfriend and he has never had another sexual partner) so i started but when i did he got soft. It made me a little embarrassed and i felt like i failed to get him off. He told me that he didn't believe it had anything to do with me, he just said he doesn't believe he likes it. So I haven't tried to do it since and he wants to try again, I honestly feel like he may just not feel comfortable and confident about his size. (i think he is on a larger size myself)

I need some advice so if you have any please help