to learn Japanese well, you must think in Japanese, young padawan...

Hiragana & Katakana is the easy part. When I started learning, it took me about 2 weeks to get to about 80-90% proficient in that with the help of flash cards. It's the kanji that is the killer, but you don't have to worry too much about that until you study for JLPT lvl 2.

自家用＝jikayou
I suppose being chinese-educated does confer one an edge in the learning process, but if you fail to take advantage of it, no point also-lah. Most of my batch which took Japanese with me are still struggling in the lower levels (after more than 5 years).

Kanji mastery is not that big a hurdle for them as it was (and still is) for me, but they fussed too much over how to translate english/chinese sentences into Japanese, or construct a grammatically correct Japanese sentence and neglected the listening and speaking parts.

IOW they phailed to use the language (i.e. learn to live/think in the language). Text books are not enough. Watching more anime and Jdorama (without subs), and actually trying to talk/think in that language is the way to go. 

That is why, to start you on your way, I recommend that you memorize your kanas ASAP and burn any textbooks that use romaji...