But 100% don't leave until you know what rights you have. You can be reasonable and say that you need, say, four weeks to research what both you and he are entitled to when you separate your lives.
As well as a solicitor, consider women's refuges, Citizen's Advice Bureau, and any other charities which give advice like this. Your GP surgery should have a list: maybe ask reception.
And I agree, given the time these things take to set up, consider flagging up your situation to the local authority. Though hopefully he is honourable and will set you up on your feet.
You might find, post Covid, somebody willing to rent you a room in their house or small business premises to run your business. Again, there will be people who can advise, perhaps on schemes to help you set up again or find subsidised premises, etc.. I'm not sure who, but perhaps the local authority, the local Rotary Club, small businesses associations, the Prince's Trust.
Finally (sorry this is so long, my heart goes out to you), a friend of mine runs what used to be a massage (and now sports therapy) business out of her car. She has a portable bed, and carries all she needs - harder for you perhaps, but hopefully not impossible - in her car (it's not v big). Her clients love that they can have their treatments at home, and she's been able to keep some business going in the last year by cleaning her equipment and wearing ppe. Maybe your ex-partner could set you up with a reasonable car, and you will have the equipment already.
I am sorry you are going through this, and I really hope it works out for you in the end.