Hi Cassey
You are NOT alone. The things you describe I and many others do suffer. I'd recommend checking out some of the support groups.
http://www.misophonia-uk.org/
http://misophonia.meetup.com/
http://health.groups.yahoo.com/group/Soundsensitivity/
these two are phenominal resources.....So many people to relate to exactly what your feeling, you don't have to feel that you're alone.
Here's a case of HOPE
http://healthmad.com/mental-health/misophonia-and-little-brown-birds-how-i-conquered-noise-sensitivity/5/
Show your parents and friends this video to help describe how you feel inside. Let them know this is a disorder and it's not something you can just "prevent" or "ignore"
http://www.youtube.com/watch?v=rlWHLx9PTE4
There are definitely things to do that can help. St. Johns Wart is a natural supplement that has helped ease the severeness of the triggers for me, others visit doctors and get more intense medication, Utilize earplugs and headphones in moderation but for severe circumstances...
Educate yourself from the info on these other sites so you can explain better to any professional doctors/Psychiatrists/Parents. Print out some of these write ups on other sites, how others are feeling....show your therapist & parents that this is real.