Just make sure you are prepared financially for a long term period of unemployment. Otherwise you may wind up in an even worse position.
That's pretty standard advice, but isn't always the right way to look at it, and it kinda all depends on your view of the world.
For some - indeed, many of those who run/ran their own businesses and made them successful - not having the financial security was precisely the motivation to make it work. If they'd had the financial security in the early days, they wouldn't have pushed and (much as I hate the word) hustled to get paying client work.
I'm not saying it's a bad thing, but it's usually the result of the "employee mindset" - security is better, even if you hate what you do.
As a silly example: my sister was made redundant from her job not-so-long ago. The work that she had been doing - and the companies she'd worked for - over the last 10 years meant she had a tonne of really good experience at being a "project manager". She was looking for jobs but couldn't actually apply for any until the last day of her existing employment or risk losing her redundancy payout. I suggested to her, and showed her how she could go about, setting up and running her own "interim project management" consultancy - being the person who "runs" a project whilst a company finds or grooms their own project manager inhouse. The amount she would be able to charge meant that she'd realistically only need to find 3 clients a year, and work with them for about 2 to 3 months each, to have the same take-home income as what she was already on. So she'd have a tonne of time to spend with her family, and the majority of the actual "work" could be done from the comfort of her office at home.
If she had a mind to, she could easily take on more than 3 clients in the year and bring in some serious cash.
She decided that the idea was "too risky". She ended up taking a job that she really does not enjoy doing, for about 2/3 the money she was on prior to her redundancy, because it's "safer".
Anyway, my point is that running your own business is inherently risky, but without the risk there is no reward.