need some encouragement

Hello all,
I am feeling a little low at the moment and need some encouragement. My story is I was diagnosed with a 7mm idc last April 05 with neg nodes and no vasculat invasion. I had a clean CT/PET scan before surgery began in June 05 and except for the small spot in my breast everything was clean. Given that it was er- I chose to do chemo and just finshed in Novemeber 05. Have been on 3 week regimine of herceptin since. In Dec 05 I started to have lower back pain lasted 4 weeks before I went to see a chiropractor who adjusted my back, my SI joint was very out of line, and it flet better. But my back keeps slipping out. Of course I have planted alot of tulips, got adjusted felt better and then moved furniture, got adjusted felt better....you get the picture. But it keeps coming back. Most days it feels great but there is always this dull sense in the muscles that it is there. I just set up an appointment for a bone scan and I am freaked out. Can it be anything else? could cancer have eaten its way through me that quickly since June 05 with chemo and herceptin in between. I was originally told that I had a very good prognosis with such a small tumor and not lymphovascular invasion or necrosis. I also had a very low mitotic count. Perhaps I am overthinking this .. I feel doomed that it is the only thing that it could be and I don't think I am ready to find out that I am stage 4. But then again I don't think anyone ever is. Can someone please help me reason through all of this. I am on overload.