Your symptoms are similar because viruses cause similar immune responses, Rhinoviruses cause the same initial symptoms as coronavirus depending on point of initial infection, viral load, immune system response. This particular coronavirus connects and uses deep lung cells in many cases and kills at an extraordinary rate. Could Covid-19 be mutated from something that we got last fall?...sure...but it is HIGHLY unlikely that this would pass from you through the human population and back to a bat, then back to the human population. Human genetics is a real science and they can track this to an intermediate animal and then back to bats as the main reservoir. It has since mutated to allow for easy human to human transmission. So don't walk around as if you have had it...you haven't...although I had the same pneumonia last fall that was unusual it wasn't Covid-19..I believe exactly what you wrote. This has been around for several months longer than most know. I have relayed symptoms to two different friends of mine, one who lives several states away in Texas and we all had the exact same symptoms. Those symptoms mirror this current pandemic. I had it back in late December and couldn't shake it for a month. As far as the cough, it was pretty brutal for about a week and then the next three weeks was just a persistent lack of energy and lung capacity. I chalked it up to garden variety "crud" which I have had before. This has been around for a while and far more have had it than the numbers suggest. I hope that suggests it will be gone quicker than they are forecasting.