a fall from scaffolding

During built- works, I was working on the scaffolding, I felt dizzy and I feel off that onto the ground. I were breaking two legs. Once has breaken in kniee and the second - tibia.  I hit on my head on the things lying under the scaffolding (barrel, spade) in hospital they discovered a bruise on brain. the police and ambulance came. I've witness. I want to stop my work and claim a compensation from my employer. What I have do first?