Get a new job. You can get a contract job paying £500 a day quite easily in the UK. Do a 6 month contract, save up some runway, work on your own thing for a while, doing whatever interests you. Repeat.
This is what I've been doing since 2018. Day rates vary between 650-750. I guess I could go higher if I was putting more effort into looking but I normally pick organisations to contract for which are fun. I like working for small startups to medium sized businesses which are tech companies, and not companies with a tech department. Big companies often come with Outlook, MS Teams, JIRA, Azure, a lot of Scrum or similar BS and lots of hierarchy, meetings and politics which makes it really hard to have an impact or fun doing work. They can pay slightly more (maybe 800-1000/day) but personally I find smaller companies more satisfying. Smaller businesses don't have time for BS, so they optimise for success, use software and tools which really drive productivity. That often means MacBooks instead of Windows, AWS/GCP over Azure, Slack over Teams, Something super lightweight or just good team communication over JIRA and most importantly, development teams often get to really make an impact, drive decisions, get responsibility and own the entire software development lifecycle from planning to deploying to monitoring in true DevOps style (as opposed to sending emails to a "DevOps" team which is common in bigger companies). I enjoy myself more in these environments and for that I'm happy to sacrifice a bit of pay.
Anyhow, I am just coming back from a 5 month break and it's normal for me to take a few months off every year inbetween contracts. I never take a contract longer than 6 months, otherwise I can't take 1-2 months off at a time. Doesn't mean I never extend a contract after 6 months, but before I extend I communicate clearly that I would like to take some time off and then basically line up the continuation at the same place for when I come back.
No, I am European but live in London (Wimbledon). The rates are absolutely UK rates. I think in the US you'd get much more, but then you have to pay a lot more as well for things which we get for free here (e.g. NHS).
How to get started? My journey was what I think is quite common for a lot of contractors. First I started as a normal employee, worked in many different companies, large and small as a developer, junior, mid, senior, then with some management responsibilities. Eventually I became just really good at my job, not just programming, but also understanding how different sized businesses work, how the politics work, how hiring works, etc. and I just felt comfortable and confident that I could get into contracting.
Initially I got all my contracts via UK based agencies (the usual ones, Gravitas, OB, etc.) but then I figured out how to look for open roles directly, either by looking in the right places or through connections which I've built over the years. If you skip a recruitment agency then you can easily get the rates which I've listed, because that's what the agency takes when they tell you a rate of 500/550.
There are lots of threads on consulting/freelancers on HN, and lots of great advice. Don't go freelancing lightly, do a bit of reading first, and ideally connect with others in the same jurisdiction for tax/billing advice.
I do consulting and 100/hour (EU/US/CA, not sure for the UK) is pretty average, and 5h/day is a reasonable number of billable hours in a day, assuming not too much time is wasted on sales (and sales can be a billable discovery phase instead, if the process delivers value for the client).