Don't panic, tomorrow is another day, 980 cals is nothing compared to binges I used to have when I was a proper chunky monkey! Don't be surprised to see an initial "sodium and heaviness of food in stomach gain", be good and drink loads of water and it will soon go.
Where your children are concerned... The fact that you care and this bothers you means you are a fabulous and caring parent. Yes the others may suffer sometimes because of J, but I have no doubt that you try and make up for it whenever you get the opportunity. Your other children are more likely to grow up to be tolerant and patient adults because of J, and that can't be a bad thing. I work with young offenders and trust me, from what I've read so far on your diary you are million miles more caring and supportive than the majority of parents I have to work with. Don't cry, just take a deep breath and maybe plan for your other children to have a bit of quality time soon... if you asked them they may not even mind if J is a part of it, in fact your kids may think you're a much better mum than you are giving yourself credit for!!! x