Take an hour a day to read some news, the articles are typically short enough that it's more "relaxation" than "work", and after a while you're caught up enough on the context to understand the significance of stories and to put on your critical thinking cap and notice agendas once in a while.

There is time to catch up afterwards. After I graduated, I knew almost nothing outside mathematics and programming, but 3 years, even just reading newspapers, will catch you up on a lot.

If you isolate yourself from the world entirely during your collegiate years, it'll be harder to re-assimilate when you're done.

Fair enough.

I've had couple 19-20 credit semesters which I barely survived; and I did not work during school. I've always admired those (especially international students) who worked while handling such workload as yours; yet excelled in their course works.

Poor excuse. (But "lack of time" almost always is a poor excuse.) Even assuming the ridiculous credits*2 hours outside of school for school work, and assuming 8 hours of sleep every night (haha), and assuming the standard 1 credit = 1 hour in class, you still have 32 hours of free time across Saturday and Sunday that you could probably spread around if you wanted.

"Lack of time" is such a handy excuse, I'd try hard to investigate an underlying reason since there are so many. As an idea of just a few, it could be that you really have no interest in other subjects (probably not if you enjoyed the article), or that you don't want people to think you're goofing off, or that all your free time is unwittingly sucked away through passive relaxation like t.v.

"Perceived poor allocation of time" seems like a real thing to me. Lately I've noticed myself beating myself up for spending time "reading/making things I don't have to", since I love random Wikipedia walks or interesting pages from google searches or reading online papers or books (even paper ones from the library sometimes), I love reading things that aren't necessarily computer related (and especially things I know they don't teach me in school or at work).

But if I beat myself up over it and/or spend time with "passive relaxation" such as entertainment (whether because humans need a certain amount of passive down time or because I want to avoid thinking about [meta-]berating myself), suddenly I can't focus enough to read those interesting things since that background thought is always present. This happened a lot last semester; 20 credits is the average at my school. (People still find time to play lots of video games.)

My current solution is to take a reduced load in the spring (possibly a gap year if my grades continue to suffer) and massively inflate my free time such that spending a large chunk of time reading about quantum physics doesn't feel like something I shouldn't do, and such that my free time isn't used up hating 6.5/7 of my classes since it'd be reduced to maybe 3/4. (There are only two classes left in my program I actually care about.) I'm glad my burnout is localized to school, though, since even some of the cruft work at work is 100 times more interesting than any of my previous semester's assignments.