Welcome to HCM
This drug is medicinal and recreational,has many psychological and physical effects,what is your age? if you have just tried for recreation then let me inform you, this is very addictve so kindly never use it again.
Even after week the drug can have many effects,but itching all over body may be a kind of urticaria
or a dry skin
. so drink lot of water and for itching may take a OTC antihistaminics once a day and if no relief then consult aDermatologist and/or Psyciatrist.
Please do not try to take such addictive drugs again.
Good Luck to you.