It is completely normal to feel that you've been raped, because that is exactly what happened. If you said no, if you tried to push him off, even if you froze up and didn't say anything, he violated you. Avoid situations where you might end up alone with him in the future. I would advise staying away from him altogether... if you still want to see your cousin and aunt, and if you and your cousin are both women, you could suggest a "girls' board game night" or something like that.

It's up to you whether or not you go to the authorities, but ultimately if you did report him you would be protecting other potential victims. Someone who does this kind of thing usually doesn't only do it to one person. Your aunt and cousin may be shocked or feel betrayed when they learn what happened (if they aren't already just as afraid of him as you are), but is protecting the feelings of two people really worth more than protecting the bodily safety of yourself, them, and others? That being said, do what feels right for you. If you choose not to report (I never did), just talk to someone in real life, whether it's a family member, a trusted friend, or a counselor (as long as they're not a mandated reporter).