www.gov.uk/universal-credit/get-an-advance-first-payment
There you go.
The other usual stuff applies:
Speak to Women's Aid
Look at the Freedom Programme course (but I think you need to prioritise exiting much, much sooner than December first)
Check whether your local authority has a DV team and what support they can offer you - you should be able to find this on their website
Get legal advice if you need it
Consider telling your GP or medical team so that it is on record
Gather up important documents like passports and birth certificates as well as any irreplaceable sentimental items
Make a safety plan with Women's Aid, including how to leave safely - usually this means leaving without warning when he is not home.
Make sure that in all of your conversations with these organisations and when seeking advice on your situation you explain that you are experiencing "domestic abuse" .
You need to use those words to make sure you receive correct advice - lots of people won't realise if you hint at it or give isolated examples, and if they don't realise you will receive incorrect advice (for instance, not being told about legal aid).
Domestic abuse. Domestic violence. Coercive control.
That's what's happening, that is what you need to tell people is happening to you. Pick the one that is the least uncomfortable for you to say out loud.
Yes, he is deliberately trying to prevent you from leaving with the financial abuse - abuse is about power and control, if you leave he no longer has that control. These are completely standard tactics.
And that is why there is so much support for people in your position to circumvent his attempts to keep you trapped.
I do get why part of you probably feels the need to keep seeking reassurance that this is definitely abuse, but at the same time it does send you down a bit of a rabbit hole that stops you putting the energy into planning your exit and getting the advice and support you need on that.
It's a distraction for people replying - who end up just commenting on the abuse and drawing you into discussion about the many and varied shitty things he has done to you instead of the help you need to actually formulate your exit plan. It's a distraction for you when you get drawn into that instead of focusing on getting away from him.
It's hard enough to break free and muster the courage to go through with it, without sending yourself off on a tangent that saps your energy and resolve.
Why not start a thread purely focused on gathering info for your exit plan (don't share too much of your actual plan in case he recognises you) so you can gather things together without so much "noise" ?