[PureStorm]

Yes, a blowjob is oral sex. Yes, it's up to you to do it or not.
You said you are scared? What are you scared of?

Here's the deal.
Denying him sex is the same as him denying you a shoulder and an ear when you need it. He denies you opportunities to emotionally bond with him, and won't be there for you when you need him. He denies you commitment.
That's how I see it. Would you be fine with him doing that to you? I'm NOT telling you to give him oral against your will. I'm just telling you to try to see it from his point of view (because you put him in a bad light for expressing his male sexuality and primary needs) so you can understand him better. Men and women are simply different. From your post I read just a little lack of awareness of that fact.
And my oppinion is still the same: it's up to you, only do it if you want it - and yes, you should leave him if you two simply are not a good match. But try to understand men when they crave sex.