I want to have sex with my bf like... ALL THE TIME.?

My partner and I have been together for about 4 years, we have sex every couple of weeks when HE initiates it. whenever I try to initiate sex with him I get turned down, I try not to let him see how much it upsets me but it's starting to make me feel really unattractive. one time I was hinting that I wanted to have sex, and he told me he would rather just go and have a bowl of weetatbix... WEETABIX!! And to make me feel even worse he looks at porn nearly every time i leave the house! I don't think Im a dud root but I guess I wouldn't know. I am at my wits end. please please any advice would be greatly appreciated.