How much were you using when you stopped? And when did your withdrawal symptoms start?
In my experience, the first two weeks are the worst. My sub withdrawals always took a few days to kick in, so day 5 of being sub free was equivalent to the first day of heroin withdrawal for me.
My sub withdrawals always lasted more than twice as long as H withdrawals too.
For me, it took a few weeks for all of the withdrawal symptoms to go totally away. Things may get worse for a few days, but they will slowly start getting a little better everyday after that.
If you can, get your hands on some gabapentin. That is a lifesaver when it comes to the RLS. Where I'm at, the ER will prescribe it for withdrawals. If you can't, rub Bengay on your legs as often as you need to, and take HOT Epsom salt baths multiple times a day.
Also, do whatever you can to sleep even for an hour (I always used RX sleep meds). As impossible as sleep seems, if you can knock yourself out for a little bit, it will make dealing with the withdrawals seem more doable. Your body needs to rest as much as possible because it's under immense stress. I always do whatever I can to sleep through as much of my withdrawals as possible, because even if it's only an hour of sleep, that's an hour I had a break from the exhaustion of dealing with the pain of withdrawal.
Making it through a week is amazing, and you are so close to being free of this. Keep going, it WILL get better!