If you're a person of discipline, I suppose you could have a regimen of allocating fixed amount of time for those activities, like 30 minutes of reading a grammar book or site, 30 minutes of watching language videos, and the like,.
Personally, I find it hard to follow such a rigid plan, so I don't even try because I know I can't do it more than a few days. So I don't think I can give you much practical advice there.
However, I think one thing that might help is to have some subject of passion. That is, see if you have anything that can drive you because you're passionate about it. For example, if you have a literary work that you really like, you might read its Korean version (or even Bible if you're deeply religious), or you might read and study works of a prominent poet or singer, watch videos of them and so forth. I think this kind of extra interest will help sustain your learning in the long term, so it might be worthwhile to find and develop such an interest.