There is so much advice in this thread, but I feel like it all just represents out particular problems we face and deal with.
But I feel like we don’t know what kind of problem the OP faces.
We know that OP started learning japanese around a year ago, and now is able to read N5 material, while facing “bad days?”
What I mean, is that it’s really little information, we cannot work with that, we can only say what we do when we have “bad days” but for many people those “bad days” have different roots. At this point without making additional question, I don’t feel like we can suggest something that will hit close. If we have more data we can build more realistic hypothesis about why OP feels like that, and clerefy them again by asking before giving an advice.
For example the type of data I would ask is:
- How much do you study japanese/day?
- Do you study every day with/without brakes?
- When did those “bad days” started?
- Have you tried switching japanese learning activity in those days to something more plesent (i mean again japanesse but another type of study)?
- Do you have days when you enjoy studying japanese?
- Why do you learn japanese? Is there a practical reason or does just it comes from you?
- Have you tried dealing with that feeling before?
- Does it (feeling) grow over time and becomes bigger or is it otherwise?
- Have you felt something like this while learning something else? Have you delt with that?
- Do you have enough energy? When you feel like you have your bad days in japanese, those days are also bad for everything else or just japanese?
- Do you see any trend’s with those bad days? Like if you slept badly it would rise the probability of a bad day? Or maybe it has something to to with amout of work/study you do outside of japanese learning? Maybe it’s connected to your relationships with people? Any other relations might work as well.
Something else that could do something with your bad days?
If we know responses, new questions will arrise so we could ask them, and by answering those questions, OP might find more questions themself that are still unanswred, and by trying to answer them they might find what causes those bad days.