My fiance is verse but won't bottom for me? What to do?

My fiance and I have been together for 3 years and I can honestly say that we are very happy in our relationship. However, I do have some concerns when it comes to our sex life. I guess I should start off by saying that I am a bottom, I have always preferred it and enjoyed it very much. I have topped from time to time over the last 15 years and it could be nice but I just feel more in my element and comfortable bottoming in the bedroom. My fiance is verse. He has been in relationships where he was the bottom and in relationships where he was the top and also in relationships where he flip flopped in the bedroom. He has been very transparent with me in regards to his likes and dislikes in the bedroom. He has said to me that he equally enjoys bottoming as he does topping. So now for my dilemma, he will not bottom for me. He has bottomed for me exactly 3 times in the 3 years we have been together which I find strange because he does enjoy bottoming. And the only reason he bottomed for me those 3 times is because I expressed my feelings about it, so I suppose he felt bad and just did it for me.(so essentially it was a pitty fuck) Now I'm not saying that I want us to flip flop in the bedroom every time we get busy but every now and then it would be nice. I have expressed my concerns to him and he has told me that he just doesn't see me in that "top way". Which personally, I find to be just a tad be insulting. Him not wanting to bottom for me just makes me feel insecure and inadequate and those feelings sometimes bleed into our relationship and cause other issues. If he wants to bottom for some hot guy that we may see on the street, why doesn't he want to bottom for me? Is there something wrong with me? Am I not good enough, or "big" enough to satisfy his bottoming needs? What is it? I need help and advice guys. Please chime in and let me know your thoughts.