My bf wants me to step out of sexual comfort zone, what should I do?

Been with my bf for 6 yrs we’ve had ups and downs, but recently took a break for a few months. We didn’t break up just a break. We’re still in love and miss eachother.  My boyfriend is also very well endowed & has a much higher sex drive than me always have an more experience, so recently during our break he told me that it’s not a problem now but it can be a problem in the future that the lack of effort I put towards our sex life can become a problem. I’m honestly someone who can live without having much sex, but when I met him he did warn me about his sex drive and I thought I can maintain it but now I feel kinda bc it’s more of a bigger deal to him than it is to me. While I was away he wanted me to send a few photos, or something he can look at Bc he doesn’t like watching porn, says he prefers to see me Bc he never gets a chance too so I sent him some photos, and little 30 sec. video. He said it helped and he likes that I’m being a little more open. But it’s not in my comfort zone to do things like that. Also with sex he wants to try other positions but by him being big, it hurts and he sometimes gets frustrated. So I just wanna know should I be open more and just letting it go? Taking the pain. And discomfort or should I stick to what I’m comfortable with. Bc I don’t want to lose him. I feel he wants me to be someone I’m now, I’m not used to being a freaky or spontaneous woman and think that’s what he wants. But idk what I do. Bc we are still in love. & he wants to marry