If you have access to Neurontin (Gabapentin) or Lyrica (Pregabalin), those help quite a bit in many person's opinion including myself, with the RLS and general state of mind. Immodium for the stomach issues. Clonodine (blood pressure med) helps quite a bit especially in the first heavier days of w/d for balancing out the fight or flight response that causes those intense sweats and chills. Any muscle relaxer is my friend at night time whilst enduring these trying times. A good absorbable multi-vitamin is definitely recommended as your body will be needing them.
Ones that are really helpful but you gotta watch out for dependence are:
Any benzos, longer half-life ones are generally considered more effective since they stick with you longer, like Valium (Diazepam) or Klonopin (Clonazepam). I only have access to Xanax (Alprazolam) but I rarely take it due to a previous heavy dependence I kicked a little over a year ago.
Kratom (plant from the coffee family grown in Southeast Asia) which is legal in most parts of the states - It stimulates opiate receptors and can be very effective in combating the effects of w/d's. This one I wouldn't recommend more than a few days as it can definitely develop a dependence as well.
General things to do:
Keep your mind preoccupied as best as possible to not dwell on the symptoms that are bothersome
Lots of hot showers/baths
Exercise, as much as you don't want to do it, anything helps including short walks
Make sure to keep eating and stay hydrated, not doing one or both of these will only compound your issues
I know many other people have additional recommendations but these are the ones that come to mind. I'm suffering through the w/d's as well right now so I feel your pain.
Best of luck to you and great job getting down to 4mg on the subs. That's no easy effort especially after 3 years of use. Jumping off at 4mg may prove to be rather difficult as 4mg is still quite a bit in my opinion after any significant length of use. When I rapidly tapered down from 300-450mg of oxy use. I inducted on the subs at 4mg and rapidly tapered from there over the course of one week and jumped at .5mg. Far from pleasant but I made it work. That led to 6-7 months of clean time for me in 2014.
Keep us posted of your progress!!!