S.B.
This is a horrible situation to be in.
I'm a single mom and it's so hard sometimes.
I often felt like I got two steps ahead and three steps behind no matter how hard I tried.
I am in California so things might be different here. But, ask if there is a school counselor. My son saw his weekly because his dad was obviously tearing him apart and affecting his schoolwork, etc.
Also, you should have a county health department that you can call. They can give you resources. Or...they should be able to. There are lots of places for people in your shoes that charge on a sliding scale or are free.
Especially when it comes to a child, they do try to help you. Here, we have Catholic Charities and you don't have to be Catholic or even religious, but they have resources. We also have the Healthy Families program which is for children. I don't know if Texas has an equivelant.
Make an emergency appointment with your pediatrician before your benefits run out for your son and ask for referrals and resources. If your son truly is depressed, surely his doctor would be willing to lead you somewhere that can help.
I hope you get some great responses from people who are familiar with your area. Make the most of the time you have left for benefits and line up some back ups.
I'll keep you in my thoughts and prayers.