history: One day I was a bit short on cash so I didn't give a homeless man any money. I felt really bad, as I always try to give something to those that are in need. There was a day that I was a bit short on cash on hand and I didn't give money to a homeless man. I usually always do_comma_ as I feel it's my part to help those in need_comma_ as I am blessed. I felt very bad that I didn't that day. I don't think you should feel too bad about missing one day!  It sounds like you're generous regularly.  I get it though.
current: Well, homeless people aren't common in my area, so that's why I felt a bit bad about it. 
next: It's hard to see people and not be able to help.  You seem really giving!