Honestly except for anki and reading grammar nothing the rest is kind of fun.
Try things like
-Do your studying before work instead of after, if you can wake up early
-Instead of evenly adding cards, add extra cards on weekends and add fewer cards on weekdays. If you have anki synced to your phone you can even get some of your cards done at work during slow times or do 10 minutes while you're on the shitter
-do extra study after finishing the "hard" study by listening to songs while following along with the lyrics. But remember that this is only if you can't do any more real study, since it is much less effective.
But really if you do nothing but anki at an average of 15 words a day youll still finish Core 2k in reasonable time. And sometime between 2-4k words studying gets a lot easier.
I wouldn't go slower than that thought if you want to read manga in the next year.
Also, if you're really short on time, I think it's okay to delay grammar until you have 1000 words or so down, because all the grammar guides and textbooks will be using those words, so they will be much easier to read through knowing their vocabulary.