[ryandrake]

In my view there is almost no reason to stay on the Language/Framework Of The Month treadmill. If you were capable of learning language X, you're capable of learning language Y if you need to or just want to. Think for a moment: Why do you think you need to learn all the new technologies? Is it because you just love learning? If so, there's no reason for anxiety--learn at your own pace.

Is it so you can remain employable in tech? In my experience, good companies are looking for those "T-shaped" people: deep experience in one or two broadly defined domains, plus some experience across domains. You generally don't need to go deep in one particular language/framework combination. If you are good at, say, Javascript, and a company actually won't hire you just because you don't know React, well, trust me--you really don't want to work there. They are looking for a cog, not a creator.

Here's my totally anecdotal advice: Pick three or four resume keywords to go "deep knowledge" on in your career, and you'll probably be fine. Early in my career I happened to pick "cross platform" and "graphics SW". Mid way through I added "iOS" and "GPS/mapping SW". Well, I'm in my 40s and still going, so it turned out alright. Notice I did not specify any particular language or framework there: I have my favorites but I don't consider a particular language or a particular SDK to be that important in the long run. I have never really experienced this language anxiety. It doesn't matter.