Have you considered studying abroad? Many universities in Europe offer English taught programs in a vast majority of subjects - Poland has very cheap tuition fees, Norway has none at all! And if you have citizenship of an EU member state, many more offer free tuition.
I'm currently studying in Sweden at Lund (BSc Physical Geography) and got in with grades CCD. A "good" university isn't just limited to the UK, in fact I think universities back in England are on a downwards spiral in terms of standards, particularly since the pandemic.
I too tool a gap year after 2020. Don't worry about your age - I think it's much wiser to begin university after a bit of life experience, whether you've been productive or not during your gap year doesn't really matter as long as you have gained an idea of what you would and would not like to do in life. In Sweden, many take several years out after finishing the equivalent of 6th form (which that do aged 19). You'll come across people from all age groups at university so really don't let that be a concern to you.
Alternatively, you could join the armed forces for a few year and specialise say in Engineering or something - many MANY transferable skills to be gained...