Ah, an "embarrassment" of riches? I remember when I was living hand-to-mouth and would have $4.37 balances and then married my husband and suddenly had $3,482.63 balances? Maybe you don't feel "worthy" and a bit like a fraud suddenly making all that money and here these people "saw" that and called you on it?

You think you're "pretending" but they don't know anything about that, but it rubs it in because you cannot prove they're wrong to yourself; you literally did not have money for the bill right that moment ("But he's not wearing any clothes!")

That could be why the "joke" of lending you money to pay the bill did not make you feel better and like the person was an adversary instead of a former colleague/"friend"? You went from job A to job B but here you are in the "middle"; A doesn't want you and you can't prove you belong to B.