I really feel for you.
I was that shitty stepchild.
As mumsnet often says, you don’t have a stepchildren problem - you have a DH problem .
Personally I think you sound as equally pissed off with him as you do with them.
For financial reasons you are stuck at the moment ( don’t you just hate it when people post ‘ leave him then’ as if it’s as easy as writing it!) so if I were you I would be trying to make the best of it - and sitting in your car on a rainy November night eating a Tesco sandwich ( not even an M&S one - come on, you can do better than that! ) does NOT cut it.
Speak to your DH before the twins next weekend.
Tell him it is utterly unacceptable that you feel forced out of your own home by their childish behaviour and he either a)makes them behave to an acceptable level or b) he takes them out for dinner & cinema/visiting granny/cousins etc.
When you come home on the twins visiting Friday I would ensure I had everything prepared. So I would swan in, make a coffee/tea and go upstairs with the nice magazines I had bought myself. Then I would run a beautiful bath illuminated only by candle light. While the bath was running I would flick through the takeaway menus and order a meal for one to be delivered in an hour. I would then nip downstairs with my earphones on and get the bottle of wine/champagne out of the fridge ( I put it in yesterday! ) . I would pour myself a glass, stick some tunes on the speaker thingy with blue tooth and get in bath. After nice bath I would sip on wine while flicking through magazines until take away came. I would have requested DH bring it up when it came -vthe can pay for it too then! I would eat my meal while watching what I wanted on telly. Then I would put a face mask on and meditate on calming energies.
In the morning I would do my hair and face then go out for brunch with a friend/S . Then i would go shopping, even window shopping. Or visit an art gallery, or a museaum, or gonto the cinema, or a craft fair, or a stately home, or a garden Center or ....well whatever I damn well fancied. Then , if the twins were staying over Saturday night I would make sure I was invited somewhere. Or repeat Friday night.
I would NOT be driven out of my home.
Another option is to speak to them like you are all adults and say that their behaviour is juvenile and if they want to keep having weekends at your home then they need to change their behaviour. Ask if you can all do somethimg next time they come - even if it’s only pizza and trivial persuit/ monopoly / etc. Make one last big effort and if they reject it then you have every right to say to DH that you will never stop him seeing his kids but they are no longer welcome in your home and you are changing the spare room into a den and one of the bedrooms they use into a craft room/ zen room/ yoga room - a whatever floats your boat bloody room as if he forces the issue you need somewhere to go when the twins are visiting. Oh and he will be sleeping in the other twins bedroom from now on as you are kicking him out of your bed until he realises he is a husband too.
It’s time to face the music ! Now bin that bloody sandwich and get home in the bath!!