Hi Sara,
What you're describing is called 'depersonalzation' and is a very common symptom with PD... What helps me is to do some deep breathing as part of what you're feeling is due to shallow breathing... remember to breathe from your tummy and not your chest..
Hope you feel better soon.. remember, it's just anxiety and it can't hurt you and NO, you are not loosing your mind... we've all felt that at one time or another, i know i have but i've found panic people to be some of the sanest folks around, lol.. prolly cause we're so 'in tune' with everyting...
Love,
Cali :)