I hate to burst your bubble but your connection setup is less than adequate for what you are trying to accomplish. I can not recommend "back feeding" any electrical panel under any circumstances.
There is only one way to safely and reliable connect an auxiliary power source to load and that is through the use of a UL approved Transfer switch manual or automatic that is installed by a qualified Electrician.
I know, people have been back feeding for years and all kinds of gizmos and non UL gadgets available, none of it meets NEMA codes and is not safe.
As a Sales Engineer for CAT and Cummins Power Systems I oversaw the installation of hundreds of generator applications, trust me you are playing with fire.
Contact a local Electrician who has performed generator work and get some professional assistance. The life you save may be your own.
