Talk to Allergy Specialist on Urticaria (hives)

I have been suffering from hives since last 10 months. I have allergy problems including asthma I took medicines for it. for time being it was cured and I didnt have it that worse again. But, I think there started the hives ,and it's getting worse day by day. I used antihistamines and get them effective for short time. also I'm unable to find the reason or the trigger that what's the allergen to me it keeps changing to me. I have contacted different doctors someone said I have allergens in my blood someone said I don't have resistance in my body my immune system to allergy is weak. I'm very worried about about it please help me it has disturbed me even psychologically