Breast implants still high and tight

I had my 350cc high profile silicone implants on Jan 5 2010. They are still very hard and tight looking and have not started to drop at all. I have been massaging them but I am afraid the implant my be too big for my body. Is it true the bigger the implant the more likely it is to feel firm? Will they ever look natural and stop looking so tight? 5' 3 110 lbs I am considering removing them or replacing them with smaller ones. I feel like I look overweight and feel like I have to hide them.