get a decent tummy, you may look silly but the weight you lose will be serious. the object isn’t to do a perfect sit up, but to do as many crunches in bed as possible over as many days possible, like 5-10 minutes every night for a month or two
you’ll feel somewhat energetic with a good diet, you can still have McDonalds and Burger King, just try to even it out with a fruit salad every breakfast once in a while, that’s just a guess.