Oh no!!! Bribie Island?!?!? All that water around you and plenty of ice cream outlets as well.

I would be putting floaties on this kid before I let him leave the house!!! Or maybe get a couple of those cheap flights to (dry) Melbourne...
I spoke to my sister in the western suburbs of Brisbane a couple of hours ago - certainly a tad damp in that there part of the world...
It took a while for me to get a turnaround from the NSD - nothing spectacular - just slowly, slowly, things stated to change - waking later in the night from the unbearable pain, feeling slightly less stiff first thing in the morning, and taking less hours to 'get going' fully, then I started to notice that I wasn't desperate for the regular pain relief - I was like "Oh yeah, must swallow some pills soon...." and so it went on.
I'm now 11 months into really strict NSD, and just the other day I ventured into the unknown territory of the LSD (low starch) and have lived to suffer and regret my adventure...
However, I am no longer addicted to codeine, and have halved my other pain meds. Soon I want to start weaning more and see how I go. I gotta tell you though, I am no longer a grouchy (well, perpetually ANGRY, more like....) ogre of a wife and mother. I work as a physio, and some days I just wanted to scream at the patients to shut up and stop moaning!!! (not good for one's professional reputation and would somewhat harm the 'return rate' of the patients...

)
The Osgood-Schlatter's and Sever's diseases tend to run a 2 year course, during which time you just have to stop aggravating activities, and use loads of ice, maybe some anti-inflammatory creams, and some gel heel cups in your boy's shoes.
My son's Sever's has completely resolved, but I am just watching him like a hawk. He has just started Roacutane treatment for severe cystic acne (after being on antibiotics for 6 months...) and one of the side effects of that is 'joint and muscle pain' so I do worry... At least he has been taking Klebs Killers for the past half year...
Hope you get a good nights' sleep - I get them occasionally, as I have been a light sleeper for as long as I can remember, so it doesn't take much pain to wake me... I treasure those mornings when I wake when it's light and I remember waking <6x through the previous night.