It sounds like you're depressed. Depression can mess with your sleep schedule, either you sleep too much or not enough... I vary, myself, between hellish insomnia for days or just being dead to the world around the clock, but if I had to guess I'd think maybe your depression is cutting your nights a bit short.
Depression also messes with hunger signals, so you're more likely to either eat too much or eat too little. You recognize that your hunger signals are probably more emotionally based and less to do with actual biological necessity, so putting yourself onto a calorie tracking plan and figuring out which sort of eating pattern works best for you might be a real good idea. Just to give you more control and consistency, and so you catch yourself when your laziness/depression/sadness turns into a cycle of no longer really caring what's going on.
Exercise might be a good thing, not for weight loss though. Exercise tends to release happy hormones which boost your mood and boost your happiness with yourself; also, getting fit (which isn't the same as getting thin) tends to go a long way towards making you happy with your appearance and with the rest of your physical day-to-day presence in your body. More energy, better sleep patterns, endorphin boosts which help counter the sadness... all those are things you could really benefit from. Exercise isn't for weightloss but it is good for a lot of other things.
Your kotatsu looks like a comfy thing, but a comfy thing which facilitaties just sitting in one place being reluctant to interact with the outside world. Also, keeping constantly warm rather than being on the occasionally-colder side contributes to the buildup of only white fat and a shortage of brown fat (brown fat's good for your metabolism, and is also created/maintained by being a bit chilly much of the time). If you're going outdoors and moving around then great, but if most of your day is seriously just sitting inside within a heated nest then you aren't doing your muscle or metabolic health any favours, and both of those things do contribute to your final bodywelght.
But really the tone of your post is one of just crushing depression. Sounds like your father doesn't understand that and is trying to attribute your sadness to things he can project himself into understanding instead.