But perhaps it's time for a little tough-love.

Your post is largely self-indulgent whining. 38 is past "the age limit" for that. But to answer the question you asked in that context, perhaps you should estimate 140 as a likely limit (today; as lifespans extend that will probably rise too).

As to "what to do," just do it! Write some code or read and understand a particular function or tackle some snippet every day -- a little self-discipline will let almost anyone find 10 or 15 minutes per day for study. You won't need to feel so sorry for yourself for not having "started programming at a very very early age." (In my case, the age in question was ~~ 40).

And BTW, try writing in paragraphs. That's good discipline too and makes your post much easier to read.