WELCOME!!!!
You've got a great reason to lose weight & get in shape...your son. He needs a mom who not only loves him, but can keep up with him. A mom who can play games with him, take him to the park & be there for him.
Start slow, but start. Coming here is a great start. Maybe you could start with simple changes: trading healthier foods for not so healthy foods, trading soda for flavored sparklling water & a 10-15 minute walk for vegging in front of the tv.
You didn't gain this weight overnight & every small step you take will help you reach your goal.
YOU CAN DO THIS!!! Each time you think that you can't think of all the things you'll be able to do with your son as he gets bigger & you get smaller.
Good luck! Keep us posted!!!