Since you can't make an escape right now, you are going to need to work toward that. I know that depression can make that harder to do, but I think you'll feel at least a bit better if you can see the light at the end of the tunnel. That may mean getting a job or using eBay to sell some stuff or taking in other folks' kids to watch them for money, or something else.
You may also take some solace with working with your children to help them become strong and independent, whether that's to help them with their homework, or hover less, or whatever is appropriate (and is age-appropriate).
Can you talk to your doctor about therapy? Your insurance might cover at least a few sessions and it might stretch if you go to group therapy rather than one on one. I hope this helps. Hang in there.