Oh my hun this really is a pickle. I am so very sorry you are going through this. You do have some options though. They may not be easy, but you do have options. Your situation is not hopeless even though I am sure it feels that way most days.
When I struggled with the timing of my own divorce and issues that arose with childcare, career etc. I often reflected on this visual: When you fly via airplane, the flight attendants walk you through the exercise of putting your face mask on...they always instruct parents to put on their mask first, before putting the mask on your child. Obviously cuz if the parent cannot breath, how can we help our child breath in the event of a flight disaster?
That said, I see you have been married for some time now. Depending on your state's divorce laws you will indeed get a settlement, division of property assets type etc. Also, depending on your personal situation you will most likely be entitled to child support and possibly alimony. It is very important to consider your stress level as well as that state of your mental health. It might be a wise choice to simply consult a divorce attorney and see what your financial future will look like. Hopefully, that will ease any worries you may have financially. Second, sounds like your marriage has been a strain for quite a while. YOU DESERVE to be happy. Start the ball rolling and allow yourself to be happy. If you are in good standing with your employer, talk with your HR department to see if you are eligible to possibly take a leave of absence, short-term disability due to this possible life changing event you are facing? That is what I did when I was faced with divorce, had a young child and needed to stay on top of my mental health. It wasn't easy, but making a plan and taking small steps towards your greater happiness is so important. It gave me hope when I felt hopeless and trapped at that time in my life.
Just my 2 cents worth...we are of no help to our children, when we need to help ourselves first. I truly wish you much health and happiness! You so deserve it! This is certainly not an ending, but a new beginning.