Learning Japanese is way harder than I though
 

To be honest I thought it would be all fun, and that I within a year would be proficient in this language. But it turns out to be way harder than any other language I've learnt. I've reached a point where it isn't just fun, exciting and new anymore. Now I really have to force myself into keeping up with translating childrens books and Japanese articles.

I think one issue is that you set standards that were too high. I would say that becoming proficient within one year, assuming that you are learning solely from books and not immersion, is probably wishful thinking. If you don't mind me asking, is learning Japanese essential to what you want to do in the future? Because from the tone of your post, it seems like you find studying Japanese to be a chore now, and not something you enjoy doing anymore. =\

Sounds like you've hit the hump. This is the hard reality of learning Japanese; once the honey moon glow fades, you find you've still got a lot of work to do. Chin up, though. Maybe it's time to try a new aspect of Japanese, or start delving more into the culture. I love to cook, so whenever I get worn out with text-book learning, I throw myself into learning to cook japanese food instead. I translate recipes and try them out. So I'm still learning, but it's more fun and immediately rewarding and gives me a breather to go back to how I felt when I was starting up.

The speed at which a person learns a language varies from person to person. You mentioned that Japanese is the most difficult of the ones you've learned so far. Out of curiosity, what languages are those? If they're of the European variety then, yea Japanese is pretty different. Instead of aiming to be as fluent as possible, I would suggest going for the fun factor. It's a fun language to speak and people are generally forgiving when you make mistakes. So don't stress it too much. =)

If it isn't fun, why don't you do something to make it fun again? I myself have many troubles understanding vocabulary and grammar, but that didn't stop me from widening my Japanese. There are kind people around who would help you correct your mistakes, and you can find them in this forum :) I think a good way to learn is to have several sources instead of just textbooks. There are manga, anime, games, TV drama and TV shows, and novels. Each gives you a large variety of titles to choose, so as long as you choose suitable materials, it's always fun to keep learning and practicing Japanese :) One more thing, Japanese isn't a language that you can be fluent in 1 year. Set the time to 5-7 years and you'll be much more relaxed. I have self-studied it more than 2 years and my Japanese is still bad, but I'm happy whenever I learn something new or when someone correct a mistake of mine.

That's all I can say. I hope you can regain your enthusiasm, and good luck with your studying. ;)

I've learnt english, german and arabic (it's my mother tongue but had to re-learn it). I learn Japanese by reading Hiragana Times and children's books in Japanese, and memorizing the words I don't know.

30 minutes a day?

No
....

14-16 hours a day

All Japanese...no more English......

You'll be fluent in a year.

What is your native language and the languages you have learned?
Keep in mind a Korean person will find Japanese as easy as I find Spanish or Dutch and a Russian will find Ukrainian.

No, not a year. I lived in Japan for a year with a Japanese family and am not fluent. You'll speak it pretty well, though.