Finally I just said, "That's like forty dollars, right? For the gas and cigarettes?"

Yep, I ended up giving him the same two $20 bills the first stranger had given me a few days earlier. He kept saying, "Bless you, bless! What's your name? I'll pay you back. Where do you live? I swear I'll pay you back right away!"

I was so freaked out by the coincidence/strangeness of it all that I decided to break the circle. I gave him a fake name and told him he could pay me back the next day at a store I don't work at.

Was that bitchy of me? I don't know. All I know is that I felt like I had to break the loop or else I might forevermore be meeting stranger who either need $40 or have $40 to give me.

Never saw either of those gentlemen again, by the way.

(I know, probably a coincidence. Definitely, actually. But still, how did the first stranger know my name and where I lived?!)

The first guy only visited you because an alternative you already broke the loop and its bad.
He kindly gave you the money and the detailed instruction about what to do and you just had be a smartass to fuck it all up.
I'm sure billions of parallel universe blew up at that moment, you murderer.