How do you get over a phobia?

Okay so I am terrified of all insects except for flies, mosquitoes, and bees and I have been since I was a kid (I'm guessing around 5ish). Before I was afraid of them I used to love insects and arachnids but then I started getting recurring nightmares about them and the fear has stuck. I don't want to be afraid anymore and I don't want my friends and family to continue making fun of me but I get nauseated when I talk about, see, or even think about them and I start hyperventilating sometimes. How can I get rid of this?