fear of spiders is common!. it wouldn't surprise me if it appeared in like a top 10 things people are most afraid of list (you're not the only one to have this fear, I can tell you that much)
also, a spider is more afraid of a human, than a human is of a spider

think about it: a spider's job is to build a web,. it's going to be terrified of any human who tries to stomp on it, or hit it, or kill it in any other way, and if you leave them alone to do what they do best, they'll just do it and leave you alone

it's like a honeybee. a honeybees job is to fly around and collect pollen from flowers so it flies back to it's nest to make honey

if you anger the bee, or stop it from doing it's job, it will sting (and remember bees prefer not to sting, because they die after 1 sting)

I hope this goes somewhat a way to help you understand that some bugs are actually quite useful. perhaps next time you're out with your family and you see something like a spider or a honeybee, watch it from a distance at it's work.