It seems that you are having delusion of parasitosis.
It is psychological disorder...monosymptomatic hypochondriacal psychosis.
It is a disease in which patient has misbelief of having infestation of insects like bed bug, flea,mites..etc
Complete physical examination should be done by expert.
Laboratory tests may be done to rule out DM,thyroid dysfunction
, vitamib B 12 deficiency and anaemia.Antipsychotic
drugs like pimozide or olanzapine may be helpful.
For the perfect treatment you consult dermatologist