How long does urticaria last? i started breaking out all over 4 days ago, and it isn't getting better.

Depends: if it is directly related to something that you ate, or a medicine you took, it will go away after you stop the medicine in most cases, if otherwise usually it is due to a viral infection, again goes away within few days to weeks, if persists more than 6 weeks it becomes chronic and requires medical attention, at any rate if you are suffering whether acute or chronic,or have angioedema, see an MD