mites in my face?

hi there,  i have had what appears to be acne symptoms, sore/ spots on face and arms. some sores will not heal for a long period of time and appears that inside is a little longish,whitish 'thing' a few millimeters long clearly visible to the human eye. you can pull it out with tweezers or a sqeeze, once out the wound heals perfectly and the other day i scratched a scab and on the underside of the scab was one of these things stuck to the scab? this is really scaring me and gp in unhelpful. could this be demodex mite? could they be this big? pls help any advice of info appreciated
jess