Any boss that going to try to make you feel guilty would do so regardless of the length of the notice. They'd find some reason. I gave 2x the standard notice when I left my last job and years later my old boss still tries the guilit trip. You need to remember not to burn any bridges; do whatever it you have to do, but do it with dignity. It is surprising how small professional circles can be and how fragile a reputation is. And, in the end, no one else can MAKE you feel guilty, they can just try to do so. If this career change is right for you, then do not let anyone quash your joy. Congrats on the new gig!!!

If it is your company's policy for staff to only give 1 week's notice then that is up to them! Do not feel guilty for finding a position elsewhere if it is better for you and your family etc., You will not be the first nor the last person to leave them in these circumstances. Perhaps you could say how sorry you are at not giving more notice in your resignation letter and suggest they amend their policy for the future so that others don't leave with little notice.

Let anything he or she says float over you and stick with the idea that you are a good person and would only do this if you had to. Tell them it is right for you and you are sorry that it is such short notice. Remember, it isnt actually your problem. Smile through it!