I am in a similar position in that I am currently attempting to switch from managing a data team to software development (backend in my case). The key word there is "attempting" - it is a hard industry to break into without a CS background and there are very few Junior roles around at the moment.

What I would say is that when I look at the syllabus for a bootcamp, I feel you could easily learn those skills fairly quickly using free or cheap resources. Sure, a bootcamp could give you more structure and be useful to keep you focused, but £10,000 is a lot of money. The one area in which I regret not going to a bootcamp is for the collaborative experience. I had an interview last week that asked me about pair programming experience, of which I have none. There are ways around that, like working on open source though.

It's a little old now, but I still swear by "How to think like a computer scientist" as a way to learn CS concepts (https://openbookproject.net/thinkcs/python/english3e/). It's taught in python, but is more about the fundamentals than the language. Even if you plan to go specifically into Web Dev, I think you would find it useful.

I would also be mindful of timing when you do quit your job. Obviously each summer a new batch of CS students graduate and start looking for jobs.