Well, people have mentioned this but try the R.I.I.C.E. program. (Rest, Ice, Ibuprofen, Compression, and Elevation.) The ice is good for a short time after the event of the injury. Then you can try using a little heat on it after a couple weeks. This helps stimulate blood flow to the area and enhances healing.
The way I see it 6-8 weeks is not a long time anymore. I did a partial seperation on my shoulder last fall, and although it is mostly healed, it still aches everyonce in a while. Actually, it has had a positive effect, I can't muscle my way through techniques, so I have to learn how to use my body properly.
Since it hurts especially when you do 2-4-kyo avoid them at all costs. Bite nage if necessary. Give your body the best things in order to heal properly.
And since you're there in Japan find someone who does Kiatsu. That might help get things back in working order. (My gf has fibromyalgia and gets spasms occasionally. When I do a kiatsu on her it helps relieve the pain and loosen the contracted muscles --gives me extra points!)
Speaking of Kiatsu (sorry don't want to hijack the thread - the police might shoot me on site) but does anybody know where I can learn more about it? I've read Koichi Tohei's writings on it. I'm more intereseted in technique rather than the stories like "It helped my golf game." Which I did to my sisters father-in-law and it helped him go out and play golf the next day. You can Private Message me on this or send me an email. Thanks!