Not trying to be dramatic, but better to have weight problems and still be functioning than falling in a heap and not functioning at all. One step at a time. Sounds like right now you have so much on your plate that in order to cope one or two things are going to have to be sacrificed. Don't be too hard on yourself about the weight gain, I'm sure those around you who love you are not concerned with the weight. I know if I spend six days in a car not eating home cooked meals I would put on weight for sure!!

Hang in there, be prepared to make some small sacrifices, but most of all look after your mental health, everything else can be fixed or tended to when things settle down.
hugs and kind thoughts be with you