Hi L.S.
This is a pretty common anxiety complaint. It sounds like D/P D/R (derealization/personalization.)
I have had this from time to time...and yes, at first it is pretty disturbing! You think what if I don't 'snap' out of this and feel this way forever?
Rest assured this is temporary/transient and you will be fine. Easier said than done...but ignoring/accepting the feeling is the best way to see it fade the quickest. (and of course continued anxiety management/coping skill practice!)
To read more:
Depersonalization-derealization symptoms:
http://psychcentral.com/disorders/depersonalization-derealization-disorder-symptoms/
Hope you feel back 'with it' soon! ;)
S.C.