How to be motivated

There are a number of things to try doing!
When it comes to overeating, I'd suggest, at least, to research and find some foods that are healthier. So, even while bingeing them, it won't contribute to as much gain.
It's really difficult to work out a diet, particularly if you're living with people who don't have great diets, either. But it's worth it to look into healthy alternatives.
Also - finding a new outlet for that stress and depression. Do you have any skills that you enjoy doing or things that you've always wanted to try? That might be a good choice to go to to get all of that stress out, rather than focusing on food. So, if you feel stress coming on, go take that stress out in a different way, maybe go on a walk, go somewhere that isn't home - somewhere that isn't a place where you can get stuck in your head and start thinking about food and self-blame. (Or, immediately reading or playing video games when you feel bad to get out of that mental spiral.)
Keep a food journal and record everything that you've eaten in a day. I did that a while back and it was pretty eye-opening for me. (I've lost about 14kgs, myself!) It will really help you to keep track of what you eat.
You don't have to feel too motivated to exercise every day. It took me a really long time to find a routine I was comfortable with and could do more easily. It's seriously an accomplishment to just get out and do it once a week, starting out.
And it doesn't have to be super intense stuff, either. Just some simple stretching for half an hour to an hour is okay.
The worst thing is beating yourself up even more when you can't stick to a routine and cycling back to feeling bad about yourself.
You don't need to stick to a complete routine 24/7 - all you have to do is put one foot forward and make a bit of effort - and you're already taking steps! Which is awesome!