On the Google discussion forum there are thousands of posts from people who lost their entire income after Google changed its ranking algorithm.
One retired guy pleads with Google to give him his traffic back before he loses his house.
Learn from these people. If you have only one web site, if that web site puts the food on the table and if you rely on Google for most of your traffic, then calling your position precarious is a gross understatement. You are in imminent danger of losing everything. Playing by Google’s rules isn’t enough. Many perfectly good sites are penalized every time Google rolls out a new ranking algorithm.
Relying on Google is fine, but having only one web site is not. At the time of writing I have 42 web sites, 9 of which produce an income. There are 3 more on the way. Of the 9 profitable sites I can lose any 6 and still survive. I’d have to let all my employees go, but there would be food on my table and a computer in the corner from where I can rebuild my empire.