I am working with one merchant who is paying me very well. But.....will they lower their payments some time in the future?
Will somebody outrank me and my earnings take a nose dive?
These are my concerns and I have a partner and 3 children to support so cant really afford to take any stupid risks.
I was in a similar position ten or so years ago. I was struggling to find profitable work after the 2008 financial crash, doing a bit of affiliate marketing on the side but not really that much that I could afford to do it full-time.
Anyway, eventually I took the plunge and struggled quite badly to make a living. So much so I ended up living on the streets for a month of two. Eventually I got lucky and got back on my feet doing casual building work here and there as well as my online marketing. I think it took me 4 years or so before I actually made the equivalent to what I'd get doing a regular minimum wage job though. But persistence and stubbornness can pay off.
I make a good living now and, as a side effect of my affiliate marketing activities, have acquired knowledge and skills that many online businesses are willing to pay highly for. So much so, it's several years since I have gone looking for work, I have more than enough as it is.
I can't really offer any pearls of wisdom other than a few things I've learned along the way:
1)If your sites are honestly solving a problem, answering questions or fulfilling a need then any tweaks that google makes are not really going to affect you. You will get copycats and competitors that come out of the blue but often they just force you to keep improving.
2)Don't be complacent though because there is always a time where you're going to shoot yourself in the foot by doing something stupid.
3)If #2 happens and #1 is still true then you can recover
4)Merchants come and go and good ones are few and far between. They can always let you down and you'll be lucky if you avoid this. There is always another one around the corner though and, sometimes, it's a blessing in disguise when one drops you because it forces you seek out another that can often work out better.
5)Don't skimp on hosting or any other services you use. Buy the best you can afford, it usually pays off.
5)Appreciate what you learn along the way and be aware that you'll build-up a ton of inherent knowledge that can only be gained by experience. Use this knowledge to sell marketing services to other businesses, most of your competition don't have a clue what they are doing.
6)If your existing income from the other business is reliable than hang on to it for a while yet, you really don't want to be homeless - it's not as glamorous as they make out.