mikaela- I am so sorry to hear how miserable you are. I moved away from all my family and friends many years ago and I remember feeling lonely, so I can sympathize. Are there any play groups you can get involved in with your kids or do you have a church or hobby you can get involved with? Sometimes those are the easiest ways to meet new people.
As far as weight, everyone goes through ups and downs.( I have been recently gaining again and working on trying to stop it.) Try to eat as best as you can on your limited budget. Look for fresh fruit and veggies and lean proteins. I know you said you can't afford a gym, but do you have a place you can take a walk or borrow exercise videos from your local library? The weight gain can stop, it just takes some planning on what you are going to eat and how you can add some exercise. I tend to be an emotional eater, but eating more has never made me feel better in the long run. It usually makes me feel worse.
The job market is tough right now. Don't get discouraged, something will eventually turn up. There is light at the end of the tunnel. You just need to keep moving through the tunnel until you see it. Start with drinking more water today,or choosing a piece of fruit over junk food, or seeing where you can get connected in your community. I have been away from all I knew for almost 20 years now, and I can say things turned around. I made some great friends and have come to love where I live. It will be okay