Can a bruise on your hip affect how you walk? I smashed it pretty hard againsts a metal bar and I think it is just bruised?

Sure. But maybe more of what is going on under the bruise. If it was a large bruise, there could be some underlying inflammation, which can lead to swelling and pain. If you hit it hard, there could be a small fracture. Probably worth while getting it checked out. Hope this helps.