Can you post a picture? (I know anonymity may be compromised, but a picture is worth a thousand words...
The fullness can either be retained/unresected orbicularis oculi muscle inferior to the incision, redundant skin and/or thick scar. The first two issues need revisional surgery, and the third MAY need additional surgery. I am very cautious to inject steroid around the eye. I actually rarely inject steroid at all, as I feel the complications (thinning of skin and soft tissue causing scars to collapse and cavitate, developement of hypervascularity or teleangiectasias (blood vessels) and finally, failure of treaments) are too risky and difficult to fix.
Remember scars fully mature at 365 days...aggressive massage therapy can help smooth out scars.
Have your surgeon re-evaluate you and if you need a second opinion, find a Board Certified Plastic Surgeon who performs a significant number of oculoplastic surgery to help you out.