You getting killed when you appear to be behind cover is more than likely because of your connection being behind the frame rate. There's nothing you can do about it but lower your ping and be hard wired. A monitor or TV 40" or smaller with a good refresh rate would help in conjunction with the other things I mentioned. But if you're venting as a casual player that just hooks his console up to a TV and plays well then it won't be the last time you appear to be behind cover and die lol.