This might sound like I'm making it up, but I am not.
I know exactly how you feel, because about a year ago a similiar thing happened to my husband and me.
We were going up to meet our son and his family to join them for lunch in Olympia, Washington. On the way back we stopped at our usual rest stop and while there saw a young couple and their dog in their car which was obviously filled with all their belongings. The young man was asking for any change so they could get gas. They had enough to get to the next little town but didn't have money and needed to get to town in Southern Oregon where they hoped to start a new job.
Both my husband and I then left to return home, but 5 minutes away from the rest stop we both looked at each other and "knew" what we had to do. As I told my husband, "I'm concerned for their dog." (Which was just my way of saying I felt we should go back and help them oout.) So, we got off at the next exit and found a gas station, bought a couple gallons of gas and headed to the rest stop. When we got there, they were still there, obviously preparing to spend the night. We gave them the gas, $20.00 and a pack of my husband's cigarettes, and wished them God's speed and left, following them out of the rest stop. The last we saw of them was as they turned off to get gas at the same station we had.
I don't know what ever happened to them, but I think if them and smile. Someone had to give them a break, and I'm glad we were chosen.
I know how you feel, ... and you will live with that warm glow for the rest of your life, and it's something no one can ever take away from you. That's the best part!