Will it fit in better over time?

Sooo. I’m a 31-year-old woman in a new relationship the last month and I really like him and we have a great connection. However, his penis is too big. I love giving head and have never received bad compliments and now it’s like my mouth is too small and my teeth are touching him. He is very nice about it and we’ve tried varying positions but maybe it’s starting to affect my confidence a little. Actual sex I feel like instead of enjoying it I’m like nervous he’s gonna go too far in and hurt me. When he has gone all the way I felt like my cervix cramped and my lower abdomen hurt and I accidentally screamed. I have looked up some pelvic floor exercises and we have been trying different positions but I wanted to know in your experience does it get better? I want to feel good and also please him without having to stop. I do feel like I’m better able to “handle” it than our first experience. Do some people just not physically fit together?