my boyfriend won't have sex with me

So it's been about a week and I'm on e I asked him to come and give me some and he's joking about it say I'll get it when he says so ... He knows I have a high sex drive and I need it plus my doctor says I Should have sex at least 3 times a week because we are trying to conceive... I don't want to cheat on him at all because I know I can get it elsewhere but in not going to I want to do right and be faithful...WHAT SHOULD I DO???????