Re: Lump near incision site/other ?'s
It can take a while for the edema to go away, particularly if a serotoma has formed, which sounds like the case here. Keep an eye on it. Take your temperature periodically (maybe every second day) to be sure you aren't developing an infection....and continue to watch for redness or oozy gunk. If you have any of those signs, you probably should call your doctor's office, but, otherwise, it should eventually go away.
I would be surprised if the pain meds and muscle relaxers are causing the pain. That would be most unusual. I could see the pain meds keeping you awake but they shouldn't cause you to hurt more. Perhaps they are having no effect on the pain. You probably should call your doctor and mention this to him/her.
How are you doing otherwise? I hope you are limiting the amount of time you are sitting, are able to walk several times each day for short distances and are following your surgeon's instructions. Walking stretches out the spinal nerves like no other activity and it helps to keep scar tissue from attaching to the nerves, so it is very important, especially in the first three months post surgery.
In the early weeks after surgery, I found I couldn't sleep for more than a couple hours at a time. I just considered it a 24-hour schedule...kind of like a new baby. I'd sleep for a couple hours, get up to use the bathroom and would take my walk around the house at that time, then recline for a bit watching TV or whatever I was capable of, and then repeat this cycle. I figured by the end of 24 hours, I'd probably slept at least 10 hours.
Rest is a very important part of recovery. It is very necessary, so if you cannot sleep over the course of 24 hours, be sure to call your surgeon.