I screwed up!! Advice please?

I wouldn't ever trust a family member to do an 'honest' inspection of a car that their relative is selling... Who's side do you think he's going to be on????
I took his word for it. I was excited. He is an upstanding, supposedly anyway, member of the Mopar community. He hosts a large car shows, I’ve done quite well before and I rolled the dice. The car is worth what I paid for it, maybe better even with the repairs necessary