What the heck is it with husbands

Ok this is a personal issue for me, but I have to vent. What the heck is it with husbands and wanting anal. My SO has tried many times and I constantly tell him that I don’t want to do it. First and only first it hurts and I run a risk of getting a fistula. I told him that if he wants to do it to me then I have to do it to him so he know what stress he puts me through. It is becoming annoying and frustrating that I want to take a nice vacation away from home. How do you enjoy this? I feel like my vagina is not enough so does that mean I am not fulfilling him his sexual appetite? Need help to those who are experienced in this please.