That’s understandable, Japanese is a very difficult language, so it will take you some time to get decent at it but it’s worth the effort.
My schedule is organised based on the time of day. I recommend finding a bit of time for everything I’m listing here, but basically : I review vocab as soon as I wake up. If I have classes that day, I usually wake up ~10-15 minutes earlier than usual and review as much as possible + learn new words or sentences. This is a pretty straightforward process in the week-ends but when you have classes/work I recommend finding “pockets of free time” when you’re on break or waiting for the bus. Try to make it so that by the time you’re home, you can just chill and immerse yourself in Japanese.
Now, I’m taking a bit of liberty with learning grammar since from N2 onward you rarely see those stuff, but I used to do it around lunch. Learning grammar should not, under any circumstance, be tedious and take you longer than 1 hour. Our ability to keep focusing on a task doesn’t exceed an hour anyway, so anything more than 1 hour will just be a waste of time when you could immerse yourself in Japanese and discover that very grammar in your immersion anyway. Don’t get me wrong, grammar is very important but you need a healthy dose of it.
So immersion…that is listening, reading, speaking, anything you can think of, just do it, and the sooner in the day you can do it, the better (more listening time = faster progress), so listen a lot. I did the stupid thing of reading a lot of stuff because I was so afraid of kanji and now I can read anything just fine but don’t understand much of what I’m hearing, so don’t be like me 
When watching a TV show, for example, have a pen and paper with you and write anything you don’t understand; DON’T pause the video to look up words, that will slow you down and likely distract you…and you’ll find yourself browsing Facebook or watching Youtube in no time (been through that). When the show ends, take every word, look for it on jisho.org or any dictionary really, and find audio on forvo.
Additionally, what you can do to make the words stick is to take a screenshot of the show when that person says the word and upload it on Memrise (I know this sounds contradictory, but bear with me). That image will help you bridge the gap between the word in English and the word in Japanese. To save yourself some time, you can install the Vivaldi browser which has a built-in screen-capture option and a notes feature to write the words (not sponsored). As Gabriel Wyner said “You have to give the language life.”.
Lastly, before you go to bed, learn a couple new words. The second best time to learn new words is before you go to bed (1st being in the morning).
That’s about it. TL;DR : review words early in the morning; learn new words after that; do some grammar (maybe while listening to a Japanese podcast); listen and read throughout the day and end up with yet another review + learn combo . And try to stay away from English subs,
Also, you might want to change it up a little. A lot of people would tell you to watch slice of life but, at what point does slice of life vocab become too easy to you? You should watch a variety of topics once in a while, because you probably won’t find words like submarine in a teen drama; nor will you find “love triangle” in a war anime. Basically treat your immersion as though you were a native who can listen to anything without much effort,
