Motivation is fleeting. You may have it at times, but more often than not, it will be non existant.
What you need to do is get out and move more. Eat less. If you feel like it or not, to it. Make it a priority just like you would a dr's appt.
Take the kids with you when you walk.
Drink water instead of caloried drinks. Weigh/measure everything you eat to control your portion sizes.
I know how you feel. I avoided mirrors like the plague. I hate not having the endurance and stamina to do things with my kids. I'm 2 months into my journey (this time) and have been dedicated. Even when I don't want to or feel like exercising, I do it anyway and at the end of my session I feel so much better.
I suffer from depression, anxiety, bipolar and fibromyalgia. I can say that all of that has improved since staying on track with my diet and exercise.
Oh...and on the occasional day that I make poor food choices, I tell myself it was one day out however many, and make sure I stay on plan the next day. I do NOT let one bad day end all I've worked for.
You can do this. You just can't rely on motivation to come, or stay once you have it. You have to just do it.