Don't know which way to turn

It's all closing in on me, I don't know what to do, I can feel the depression I had for years whilst married creeping back, just simply because I have to think of him.
Him and his solicitor are pressuring me to sign the divorce petition, but I want to be free of him completely and I won't be until it's decided what happens to the FMH and I know for a fact he'll never agree any kind of settlement.
I'm told by our son he believes because he's part owner I can't stop him coming here to visit our grandchild (our son & pregnant partner live with me) this has caused arguements between us, so they're currently avoiding me.
I work on average 60 hours a week, am in debt, can't afford a solicitor, son doesn't pay anything toward household expenses, says he'll pay me in a lump sum once he's received a substantial amount of money which STBX unfortunately has control of, naturally he doesn't want me to survive so is delaying it for as long as possible.

Despite the fact stbx has inherited shares in two properties and a thriving business (he doesn't have to work now) he believes the FMH should be sold and we have half each, of which it is nothing because there's a huge charging order on it for an old debt of his.
I'm in this position because he chose to run off with a woman he'd known for a few weeks, and is no longer with!

Don't know how I'm expected to go on, feel so alone

It sounds like you need it sorting. You can agree to divorce petition, then enquiry about financial settlement. When it comes to it, he and you will have to fill in the form E (How much have you got and where).
From there you can fight your corner...you need to be housed and are also housing other family members.
I always think what's the worse that can happen?
Viewing it from that point means everything else is a bonus.
As it stands currently you and your family are housed. You are working like a dog, you pay all the bills.....You are doing great

You need the Decree Nisi before you can arrange a legal financial settlement so if you want to be properly free you have nothing to lose by signing the petition. The position you are in sounds so difficult you might feel less overwhelmed to proceed with the divorce knowing that there are lots of opportunities for negotiation about finance before the absolute and however it works out once done you never have to think of him again.

Thank you for the advice and moral support. I agree with you that I should sign the papers and what will be will be.

I emailed his solicitors, told them ideally I want to be free from their clients control and whilst we share a joint mortgage (that I pay) that won't happen, but I'll sign the papers and hope we can settle amicably at some stage.

I've had years of agreeing with him to keep the peace, nothing has changed except he can now afford to pay to have me bullied by his solicitor too!
What a complete waste of 23 years of my life!