Get the GC first, bro. Nothing is more important than GC if you want to stay in the US. You have a family to take care of as well. It seems like you have already pursued your Masters so there is no reason to jump into PhD right away by sacrificing your job and GC opportunity. You do not want to ruin your chance of getting GC just because you are bored with your job. Who is not bored with his/her job? If I was in your position, I would not think twice to work on to get the GC first. Good luck!!