I feel bad for the fly I killed :(

I was walking around and I put my finger near a window and all the sudden, I feel something. I look and it's a fly. It didn't fly away and it moved a bit during that but after that, it didn't really move. I was disgusted by what just happened so I grabbed a spray that had bleach in it and sprayed it multiple times. It appeared to be dead but I research and realize that bleach isn't a quick kill for a fly and I was panicking because I didn't want the fly to suffer. I come back three minutes later and it's slowly crawling in the bleach foam, I had to put it out of its misery at that point. I feel pretty bad for making it suffer like that