How to use my 10k p/m social media revenue to safeguard my future

So, I basically make 10k a month on YT (which I feel very fortunate for) but am worried about its longevity. One algorithm change or policy tweak and my revenue could drop or disappear completely.

Any ideas how I could use a portion/part of the monthly revenue to make sure that – should anything happen with the channel – I would have some sort of financial security?

Currently thinking:

– Pay more towards mortgage
– Set up a business (but what?)
– Invest (but where, I’ve never done it before)

Any suggestions or guidance very welcome. 😊