Yes, we know the western media is either lying or misrepresenting the truth.
We also know Russia lies a lot more than the western media. The Russian media is basically controlled by Putin, whereas the western media is not controlled by the government.
What you have to remember with the western media they often use "might" or "may". They look at Putin and see he's looking a little peaky and then write a story that he "might be ill".
You have to be able to read between the lines. A lot of people can't, therefore they're manipulated. However with Russia you kind of know there aren't many lines to read into either. They've used something like "strategic rebalance" or something to mean they're literally getting their asses kicked.
I've not see anything saying all his generals got killed, some of his generals, yes. And how do you know whether it's true or not? You can't dismiss it as fake, but you also can't say it's true, because you don't have confirmation. However I'd say there's probably some truth to it. It's war, generals die in war.