This:
He had repaid 1 or 2 coins since the settlement deal, which made him seem more trustworthy in my eyes. He took a few smaller loans from me, and then eventually managed to get a rather large loan, which he promised to repay a few hours ago. He's been ignoring me and missed the payment deadline, which is the final nail in the coffin.
Is very worrisome, the guy did not pay you and then the guy pays you a small amount and you make him a loan again? I'm sorry to tell you this, but you should definitely stop lending money to people because You trust too much on unknown people. and this is not a good thing. Have you checked if he has an account here at bitcointalk?