I'm not entirely sure how much you're trying. Honestly, you say that he will only get more sex if and only if it's more of the sex YOU want. Well, the type of sex you want doesn't do very much for him, trying to give him more of what you want is not going to be more satisfying to him. He likes chocolate, you like vanilla. Giving him extra vanilla, double vanilla, vanilla with vanilla on top, is not going to do anything for him. It seems to me that his wants don't matter to you really, or at least don't matter enough to do something for him. You are only ready to do stuff that works for both. You feel like you've made all the concessions you can, but you also admit that you never do anything outside of your comfort zone. What kind of concession is that - only doing what's comfortable to you - there is no concession in that... You stay within your comfort zone, do nothing that is remotely challenging to you, and wonder why he is dissatisfied. Your comfort zone is disappointing to him. You're confident that he wants a crazy porn star (which I am sure he never said to you, you probably just "felt" that way, without bothering to check if your feeling is correct). It is quite possible that he wants average, middle-of-the-road sex, nothing crazy, but all he gets is a lifeless body lying on the bed, waiting for it all to be over. That's not sexy, that's not seductive. There are blow-up dolls who are more sensual than that.
When I read what you wrote, I only see you talk about how you feel, what is comfortable to you, what you like, what you don't like, what you're ready to do or not. That's great. You know what's not great? What's not great is the complete lack of concern for his wants and needs. You exaggerate his wants and needs out of proportion, you claim he wants a porn star because to you his legitimate sexual needs are too much, so you mock them. You say that having sex once a week is so generous, such a concession on your part. You don't really care about him, you only care about the relationship. You're not ready to do anything whatsoever for him unless it does something for you too. You're only ready to do stuff for the both of you.
That's not true love and I wouldn't bother trying to save a relationship like that. If you're not ready to put the other person's needs first at least once in a while, then this is not true love. Doesn't mean to sacrifice yourself completely and become his slave, denying your own needs forever, it's not about that at all. What I am saying is that you don't really care enough for this person, that's why you would only give him what he wants after excruciating negotiations and nitpicking about every single condition and requirement that he has to satisfy for you before you're ready to do anything.
If you choose to end this relationship, this issue will crop up again and again until you meet someone or are ready to do something 100% for someone else, putting your own feelings about it on the backburner at least this one time. And it is quite possible that you may never meet a person you care deeply enough for, that you would do anything for him, even something that is not 100% to your liking and in your comfort zone.
Ask yourself this question - why do you care more about "the relationship", "the two of you" when you obviously don't care about him? How can a person care about a relationship but not about the other person? Because that's what is happening in your life right now.
Are you afraid of losing him, or are you afraid of not being a team of 2 anymore? If you break up, are you going to miss him, or are you going to miss being a couple? In your mind, is the partnership more important than the individual's needs? Because if it is, it means that you don't love a person, you "love" an abstract idea about a team of two.