I completely understand your concern and I hope I am able to help you for the same.
You seem to have developed chronic urticaria
There can be many cause of it.
Hope you are not on any drugs.
Pain killers and antibiotics are common offending agents.
Even certain foods can lead to urticaria.
You need to get certain blood investigations done to find out the cause.
Autoimmune diseases, any kind of body infections or worms in intestines are other causes.
Take oral antihistamines to relieve the itching.
See a dermatologist
for proper assessment.
Hope it helps
Best wishes for a speedy recovery
Dr Geetika Paul