Is this an actual phobia of am I just scared of them? *much crying in this description*

So, this is about spiders, go figure, haha. I am absolutely terrified of them, mostly in my room. It's the same with Crane flies. Whenever I see them I start sweating and with spiders I'll run straight out of the room and I'll start crying, I'll avoid going into that room for hours, sometimes a few days. Almost every time, I start crying. As I'm still a teen, I live with my parents. They aren't very nice about it, they say I'm overreacting and they get mad at me. Several times there was a crane fly in my house at the dinner table, in my family we aren't allowed to get up until we are done. I watched it every second, and eventually it got close to me. I bolted up and stood in the corner of the kitchen (fork still in hand) and started crying. (yeah, I cry a lot when it comes to this stuff, heh.) Another time I slammed the door shut to my garage because it was coming near the enterance to the house, it got in and I ran into my room, refusing to get out. ANOTHER time, there was dog hair arranged in a way that looked like a giant spider in my room, so I ran out and yelled for my dad to kill it. He refused so I refused to go into my room. As always, I was sobbing my eyes out. The weird thing is, this only happens in my house. In public I'll just look at it and walk away from it. Is this an actual phobia, or am I just ridiculously scared of things for no reason? Thanks.