How to help my morbidly obese son lose weight (10 points for best advice)?!

How to so my son is seriously morbidly obese hes 8 years old 4'2 and 366 pounds has a 85 inch waist ( which means his belly is bigger around than he is tall which scares me knowing that to be healthy your tummy has to be half of what your height is) his body fat persentage is 61% and has a BMI of 102, and his pediatrician said if he keeps this up he will have a heart attack at about 20 years old. i blame myself for him being like this i always coddled him and when ever he wanted food i gave it to him. he is a coach potato who watches tv and plays video games all day, and he eats very unhealthy (which is my fault for feeding him greay and fatty foods) he also eats alot, for example one night my daughter caught him eating all the twinkees, brownees, cup cakes and cookies i had bought that day, but when she caught him he was fast asleep and it was too late he had eaten all of them (he ate 6 twinkees 12 fudge brownees, 4 cup cakes and 6 cookies in one night which amazed me appernetly he ate really fast and was stuffing multiple amounts of food in his mouth at once which makes me thing he knew what he was doing was wrong. he also likes to sneak food one day i saw him walking to his room and i just motherly kissed him on the cheek and hugged him i felt these weird lumps around his sides so i asked him to pull up his shirt and he was hiding twinkees and snickers bars under his fat rolls so that i couldnt see them and i asked him if he was hungry and he said no i just wanted to eat them. i tell him he can only have sweets for dessert but he finds ways to sneak them. also i catch him playing with his belly fat. i asked him "what are you doing with your belly" and he starts jiggling his belly and replies ", look mommy my belly is like jello see how it jiggles,"and started smiling and laughing it makes me think he does not know what being obese is and the risks he has. my husband is a healthy weight he is 6'3 and 185 pounds but eats unhealthy and is lazy so i guess my son got his habbits from him. and i have a 16 year old daughter who is 5'2 and 110 pounds so she is normal weight ( shes those types of girls who doesnt eat alot and gets full quikly so the food she doesnt eat she will give to my son. i am 5'5 and 130 pounds so im thin and am able to do physical activities with my son. as for now he gets tired very easily he cannot run for more than a few seconds untill he gets aches and pains. and really cannot walk for more than 2-3 minutes untill he starts high breathing and has to sit down he can not do any sit-ups because his tummy is in the way and cannot do any push-ups because even when he gets into push-up position his belly is too big to get off the ground. so i want to start off slow and then intensify activiteis as time goes on. we live in Houstan, Texas so it is warm all year to excersise outside. what im asking is
what diets or healthy recipes can i use that a 8 year old would like?
what are some fun physical activities an 8 year old would like?
he likes football and baseball he used to play until he got too heavy to play.
im desperate i love my son with all my heart hes my baby and i dont want to lose him