This is certainly not a medical opinion, but just my perspective and experience with "black and blueing"; based on my resurfacing experience, and 50+ years of sports injuries. When you have an injury or surgery, there is bound to be some internal bleeding from whatever was cut or injured. This fluid accumulation leads to swelling. As the blood that causes the swelling sits for awhile, it gradually turns black, blue, yellow, etc, until it is gradually absorbed back into the body and transported away. So basically injury=swelling=pretty colors. The solutions are to not let the blood pool in an area, though elevation, icing, and movement; all of which help to avoid the pooling=swelling=pretty colors. Sitting at the computer with your legs not elevated gives gravity a great chance to pool the fluids in your lower leg, so maybe avoid that for a few more days if you can.
If it makes you feel any better, many of us went through our little "freak out moments" at about your point in time. For some of us, it is just part of the territory.
Best of luck on the rest of your recovery.
John