I have had a double mastectomy ( invasive lobular and ductual cancers) and also opted for immediate expanders since 8/21/02. It is ten months later and I've learned that more time between the fills helped in allowing the area to heal and minimizes the pain. Pillows to prop my arms at night when I slept balanced the weight of my arms and prevented my arms from falling asleep (pins and needles would wake me).
I am planning a combination reconstruction of a partial silicone implant with a latisimus dorsi back flap but need to wait another three months for the area to soften. The typical scar tissue encapsulation has occurred and my hopes are time will heal and allow this tissue to relax and soften appropriately. I had no idea the expanders would be this uncomfortable and painful. In the beginning, I actually slept almost upright on my sofa with pillows because lying flat was way to painful. As time progressed, I slowly was able to eliminate some of the pillows and return to my bed. This has been quite a journey. Good luck to you.