Keep drinking water and taking vitamins, that is one of the best things you can do. As for the RLS, walking and hot showers/baths do help, but the RLS syndrome should go away very soon for you as you are on day 4. Most of your symptoms should subside within 7 days (counting your 4, so only 3 more). As for the fatigue, that will last a couple weeks, but when your other symptoms go away it's really not the worst feeling.
Hang in there! Opiate withdrawal sucks, I have been there myself many times. You will get through it, although you might often find yourself thinking about amputating your legs! The best advice I can give is to REMEMBER THIS FEELING. Our brains often try and trick us into forgetting the hell we went through getting off these things. Every time you kick it gets worse so why not make this your last.
Best of luck to you! Keep us updated on how you are doing.