Get used to that feeling if you want to be a web developer. You are in one of the most "churning" areas of software technology. None of today's popular JS frameworks were around even a few years ago, and in a few years time I expect we'll see an entirely new set of popular frameworks.

Forget about the "long run." Pick something with a decently-sized community of users and support. Learn it well enough to do what you want to do. Expect to throw that away and learn something else next year. The era of actually achieving "mastery" of any development tools is long gone, at least in the world of web front-end development.