Ask HN: How to stop over browsing/consuming information and start learning?

I am 40 and an electrical project engineer. I have no formal education in CS related fields.

I have this very bad habit of excessive browsing of HN, Twitter and Reddit for intellectual/math/programming/CS related contents even though I don't work in a industry which has any use of this. I have this constant urge to save everything I find interesting (through quick glance). This becomes more problematic because I usually have too much spare time. I have save thousands of links and PDFs but rarely have gone through any of them in detail. I am interested in too many things.

I was thinking today that in last one week I haven't actually learned even a simple thing in either math or programming or CS. In fact the stuff I have learned in last one year could have been learned in 1 week.

So how do I start actually consuming the materials in dedicated way? How do I control the urge to check HN or anything like that every now and then and start focusing on actually learning something? How do you tackle this issue?