my big mistake as new owner

I first time having dog so I did not know anything. I buy the big bag of dry food and think more is better, so I give Bruno double portion for 2 months. Now he is so fat he cannot walk to the lift without stopping. Vet say your dog is overweight, too much food, not enough walk and I was so embarrass in front of the doctor. Now I measure every cup and walk him 30 min morning and night in Ratchada park. He still lazy but better. Lesson: no more free food for him, even when he look at me like that.