You are implying that there are more democratic gerrymandered districts than republican, that is simply untrue. Districts are redrawn after a census, census data is completed ever 10 years, the last one was completed in 2010, the last midterm that republican gained control of most states. This enabled state governments to redraw district lines to ensure that their Republicans party would safely be in power.
How else can you explain a 9% approval rating, with a 90% re-election number?
Its all good though, most people expected this to happen, its not denial, it was predicted. And as most have already acknowledged, it just gives Democrats a better shot in 2016 to regain control of the senate, and keep the White House.