I crushed a little small baby spider through the brick

I can’t stop feeling bad. I killed a little harmless small spider brutally. Literally crushed her into pieces. I sleep on mattress on floor and last few months back i had red spots on my skin and today morning i also felt something was crawling on skin. I am generally very afraid of spiders very much. In case of cockroach and other insects, i usually pick them from some towel or something and throw them away from door. But today impulsively, i crushed that little spider. after i see her crushed, I had a burst of cry. Will karma hit me back and a spider will hurt or kill me in some way, I am so afraid of spiders and arachnophobic, what sin have I commited?