how i trick my brain into euphoric states or something like that
I end up doing this thing a lot where I buy something that I think is where I'm at, and it turns out to be just a bit too exhausting to use at the moment, even if technically I could use it if I was really determined. So I just set it aside and only keep up with the regular routine, and the next time I poke it, it feels like I've made a significant improvement.
Generally this doesn't seem like it's in keeping with a lot of the advice you'd get from people learning ... anything, really, because just avoiding something that's hard means you'll never really improve. But that is sort of my way around the feeling of stagnation and demotivation being at this kind of intermediate stage tends to lend to. If I avoid 'checking' for a while on something that's hard, then even the relatively small progress I've made in the past three months feels more exciting. "I couldn't read this before, but now I can, and it seems kind of magical because I wasn't trying!" kind of thing.
As opposed to if I had pressed myself and made myself read these materials then, I probably would have had the same result (or better), but I also would have had a month or so of feeling really frustrated with everything I was trying that might have made me stop everything altogether. It seems like since I keep doing my 'regular' things (vocab/grammar/'conversation' practice), it's kind of okay even though sometimes I stop doing all the 'extras'.
Honestly, I know it's popular and I do think there might be some benefit to it, but immersion is far too difficult for me to sustain without becoming a source of demotivation in itself. I watch English-language programs on TV (well, on Hulu and Netflix) and almost none of my friends know any Japanese, so 99% of my conversations are English, and given I've always had trouble with audio processing and audio learning anyway, especially in the case of understanding music, I don't really go out of my way to find Japanese songs to listen to either.
From my own experience, I feel like it's far more important to like what you're doing and do it at all, even if it seems like you're hardly doing anything (my study time amounts to maybe 5 hours a week max, often less, including time spent 'passively' studying since I often don't do that at all), than to stress yourself out about how much or how well you're studying.
Though I do say this as a learner who assessed the life options available to themself and decided that it's not worth it to me to quit doing everything else I do (work as a programmer, drawing, having any sort of meager social life) to study language(s), just to learn them more speedily. So obviously if your goal is to learn a language to your desired level in a short period of time, it's probably going to make you unhappy to move as slowly as I probably am doing right now (I guess? I don't know how to judge how slowly I'm learning anymore..). Sacrifices always have to be made, but minimizing stress ends up being key for me. And since I just can't have more time, I had to learn to be happy with the idea that I might be forty before I'm really where I want to be in both Japanese and Mandarin.