First of all please remain calm as you didn't really do anything wrong, it is risky sometimes but we've all done it before and it doesn't make you disgusting. You trusted him, saying you almost married and you were having a relationship. So it isn't your fault, you can't control people and how they contact you.
It is also less likely that the videos will be spread as you are panicking about, i've known many guys who keep such videos on their phone for years but it's just for their own use. It sounds like you come from a conservatve background so you mentioned your family and i guesss family honour. Is this guy a family friend or someone random? Sexuality is private so don't be ashamed of that, im sure you didn't do it thoughtlessly or you wouldn't have done it if you thought he was a total liar or someone terrible.
As above user said you have not ruined your life at all, tbf it sounds like your anxiety of imagined consequences is making you really scared but it is currently in your head. you have his texts and im sure he sent you things too it's not like you did some mindless outrageous thing, you had a relationship and it was mutual. Therefore he would be stupid to share anything as he has the same need for privacy.