You don't have to defend yourself or your feelings. What you feel is normal and many would feel like you do in your place. Nothing of what you've said sounds ridiculous or stupid or anything like that. If anything you should defend your right to express your feelings, be it to us or your partner.

What I find unusual in this case is that he was verbal during masturbation but he's not during sex (do many men here talk during masturbation? Because I personally thought it was rare). Maybe he has his own insecurities too. It's the part that would bother me the most, as I'd expect him to be "all that" during sex instead of by himself. That's worth discussing.

As to whether he prefers large or small breasts, he's been with you for so many years, there's no way he'd prefer large breasts and still be with you for all this time, you'd have noticed something or he would have said something, or he wouldn't be attracted to you in the first place. Porn doesn't go hand in hand with actual, real preferences and it's rarely about the people shown in them, it's mostly about what they do.

I'd also like to know how happy you are with your sex life and if you feel he cares about your satisfaction, plus if the frequency is good enough for both of you.