Hi there and welcome!
The best way to ensure stability as a virtual assistant is to invest yourself, your time, your energy and your expertise in the foundation of your business and then market, market, market.
The great thing about being a VA is that you're a business owner, so you're 'in control' of what happens in your day to day work life - but the flip side of that is that it's ultimately no one's responsibility but your own to create a viable business model, maintain it, and bring in new clients/income.
Taking the plunge in that direction has been the number one best decision I've made in terms of how to spend my time bringing in money but it is a lot of work...totally worth it though!