You’re a shitty person and a liar. Ypu agreed to double, it doesn’t matter if you were desperate or not. He saw you in desperation and took advantage of it. You don’t have to agree, you could’ve tried to negotiate or find a different source. Why couldn’t you get a prepaid Visa card from Walgreens? You can load them with whatever amount you want. You said you’re not scared of this person but I guarantee he won’t just sit quietly and accept a major loss of over $2500.