3LM: It's so hard when your DH isn't on board. My DH could do with losing 10-15kg, but he stopped trying a long time ago. Luckily he and I have different tastes in junk food - my big weakness is chocolate, his is soft drink (which I don't care for). If DH does have takeaway, he tends to eat it when I'm not around. He may not be losing weight, but he's supportive of me losing weight and does his best to help out by limiting temptation.
You've got to be do it for you. Maybe talk to your DH?

And definitely DON'T feel guilty about going for a walk! You are improving your health! I know the feeling though (need to take my own advice, lol).