So I've been learning japanese for about 2 months now and so far I'm making I would say good enough progress considering the fact I suffer from ADHD meaning I forget alot of things and I get distracted easily
so far I learned around 500 out of 2000 kanji, the whole hiragana and katakana alphabet, how to count to at least 100, basic things to say in a restaurant, and ways to say hello and goodbye other than こんにちは and さようなら
so some people might thing "why is this kid bragging about how much he learned?" but in honesty, I mainly typed this to incourage people and get them a bit motivated learning the langauge that they can do it if they put effort into it. So far the only problem I find is I don't know how to learn grammer, hold basic conversation, and my ADHD, which is why I'm on the site so I can chat with some japanese speakers(if I can find one at least-_-). I'm telling you guys to hit the langauge hard and you can do it, If a person like me who gets distracted easily, forgets things often, and focuses more time on setting up for student exchange and school, then anyone can do it as long as effort is put into it.
good luck on learning the language you want for any reason you're going for and have some bloody fun while you're at it!
P.S. if anyone is interested on finding out how I'm learning japanese, feel free to send a message じゃ な！
You sound like you are worried because you have ADHD, but who cares!?
My English is not perfect, but I use it for my job.
As much as you enjoy learning and using Japanese, that is what language learning should be.
If you forget something, you can study again.
Who taught you that you have to remember everything you learned before and progress your skills all the time?
I feel you got a lot of motivation to learn Japanese!
Please let me know if there is something I can help. :-)