In the past I found freelancing in the UK highly dependant on personal network. I believe it is possible to find work if you know enough folk who are happy to work with freelancers. I built my network by attending interest/tech based events and networking.

An alternative might be contracting but these usually require setting up as a LTD, getting insurance, etc. you’ll also have to deal with corporation tax and other admin. The work you’ll get is more or less the same as perm work but with more risks (usually 3 or 6 month contracts, you’re the first to get fired if things get tough)

However day rates in excess of £500 are normal outside of London (£750 in London) so if you can deal with all that it can be lucrative. I use 220 as the number of working days in a year which can put your income north of £100k (ymmv).

Hope that helps, and hope you work it out.