I know about cold urticaria! A friend used to take an antihistamine each night to keep it under control and not have to worry about an 'attack'.
Your case sounds really severe. Maybe if it doesn't happen all the time anymore, perhaps it's a sign you are 'growing out of it'? I hope so.
I hope I grow out of it! At least as I get older I'm less sensitive to the cold. Which is really helpful.
Those antihistamines are truly life saving. I don't know what I'd do If I had an attack and I Couldn't combat it with anything.