Fatties in their 40's

Hi... yes I'd also like to shed some lbs and gain some strength before I get smacked by 50. I've got a 3 year old so I need to keep my health good so I can be around for him for a long time! I'm not trying to get back to my 25yo weight but if I can lose about 30 lbs I'd be very happy. Between metabolism changes, sedentary hobbies, loads of time in the car shuffling kids around, and a kiddo with endurance issues (makes it hard to walk around) I find myself weaker/bigger than I expected I'd be. I'm at 1200 cal a day and going to the gym at 5 am 2-4 times a week (when no ones sick or I'm not injured). I hope too run a half marathon in 2018...