I've been learning computer languages since 1961. I definitely gets harder. The first time I noticed it I was in my late 50's and was learning Web develeopment (SQL Server, ADO, html, Javascript). When I was younger I could read a manual, remember it, and get to work. With the Web stuff I was working with a circle of books on the floor around my chair. Now I don't use books any more, just Google.
Part of the problem is getting older and not remembering details so well. Part of the problem is that there is SO much more to remember. Fortran had a dozen or so constructs to learn. Modern Web systems have thousands. My opinion is that modern programming systems would be unworkable without Google. Even the young people couldn't remember it all.
Would I hesitate to learn a new language now? Probably not. I just did some work with Camel for the first time; it was slow but I got through it.
So, all the advice about career paths is probably good, but if you like to code, I'd say you can still do it.