Is watching porn cheating? (Updated)

So all my life ive had a bad self image, i was quite chunky in the beginning of highschool but nearing the end of highschool the stress from my toxic relationship caused me to stop caring about myself and stop eating.. 3 to 4 months of barely eating and i become anorexic which obviously resulted in even lower self esteem. Fast forward to today and i have a new boyfriend, he takes really good care of me but has a huge bubble butt fetish witch i am unable to fulfill(he closes his eyes during sex) ive been trying to gain weight and exercise to have the body hes into but being anorexic makes it very hard to gain anything/ keep the weight on which leads to him not being sexually fulfilled and constantly seeking out any type of nsfw content he can find via youtube, pornhub or movies. We share an account so it pops up on my suggested constantly all these clickbait half naked girls, every time i leave the house or the room or look away hes staring at these thumbnails its obvious because hell go back over the same picture 4 or 5 times before realizing ive noticed and moving on its to the point i cant fall asleep on the couch beside him without him searching for these girls and it hurts me deeply. Ive explained to him that im aware that i dont have that satifying of a body but if he would please respect my insecurities and not seek out other girls because im trying to have a better self image and hes not helping but the only response i get is a huff of anger but when i ask him why he resorts to exploding he just says its "embarrasing" and "he doesnt wanna talk about it" but continues to do it. Ive even tried to be open minded and try to ignore it and let him look at what he wanted but this resulted in me having an uncontrollable panick attack and him not giving me any type of attention at all. I dont wanna have to break up with him but hes practically told me hes not gonna stop and im going to have to deal with my emotions. Please let me know if im being overly jealous and unreasonable or if seeking out "hotter" girls is "normal" in whats supposed to be a serious relationship.

Id like to add that i didnt take watching porn as a threat in past relationships this only recently started occuring when he started turning down sex because hed "rather masturbate". I have an extremely high libito which is honestly higher then his and could go at it pretty much any time he needed and more but he chooses to seek out videos instead.