Sorry to hear this OP - you have a lot to deal with and certainly deserve some comfort.
However, using food as comfort is not a great idea if you are already overweight. It could well end up making you feel worst and literally add to your burdens.
(Feeling tired often makes food even more attractive. I think that the body associates the feeling with being a bit low on calories and needing a boost. Sadly, if the tiredness is for other reasons, then eating won't work and probably makes you feel more miserable.)
Dieting does require some time and energy to spend on yourself.
This does not seem to be the right time.
Instead , could you consider other possible means of comfort?
Having some quiet time in the house is good. Could you find non-eating ways to enjoy that restful peace? (Burning lovely candles -reading- knitting - doing gentle yoga - watching an episode of something fun and engaging?)
Walking in fresh air is great - as is meeting and enjoying the company of good friends.
You could try things that seem like expensive luxuries to you. They might cost more than food but will help to remind you that you are worth more than you think and that you deserve treats. (Confidence and self-worth are very attractive qualities even at 3 stone overweight. Boosting these things is important in helping you cope with your very demanding real life too.)