Look, don't get down on yourself. The only way to get more experience and get better is to do more raids. Do it as often as you can, regardless if you already have your rewards for the week. You will get the hang of it in no time!! Also, try to find a group of regulars to do it with. Randoms can turn out okay, but it is much, much better to have a group that you run it with all the time. You get to know each others play styles and who is better at what [even though everyone should be able to competently handle all roles]. Good luck!