Considering I live in Canada, I see a lot more propaganda from the Western media and Western governments than from Syria or Russia. I do read RT, as well as Al Jazeera and the China Daily. RT certainly does as much "fake news" as Western media, but it still gives a lot of true information that we never hear in the West.
If you want an example of propaganda, just look at you when you said, "Assad killing women and children". Guess what, everybody kills "women and children". The US certainly killed a lot of women and children in all its wars. It is said that the consequence of the Iraq war was about 500,000 civilians deaths, and of course it was not only men. (BTW, since when it is OK to kill men?)
Considering the situation, it seems very unlikely to me that Assad decided to launch a chemical attack. Chemical weapons are mostly ineffective from a military perspective and extremely bad from a political perspective. They are only good for terrorism. Assad wants to stay in power, and since he was winning his war, for him using chemical weapons makes no sense at all. Maybe he's not the best diplomat around, but he certainly showed that he does play his cards quite well.
There are at least three scenarios which are more probable. It could be some dissenting high-ranking military who are trying to provoke the fall of Assad. After all, the FSA came from the Syrian military. Or it could come from ultra-nationalists in the military who acted on their own, like what happened for the first chemical several years ago. Finally, it is certainly possible that the strike hit a stockpile of the rebel's chemical weapons, since it is known at least some rebels do have chemical weapons.
One thing is for sure, the US did use the alleged attack as an excuse. It was waiting for this kind of excuse. For years the US has been arming rebels (including indirectly jihadists) in order to do a regime change in Syria and to put in place a pro-US government. It didn't work and Assad was winning his war. So I guess the US had to do something.