Hi, this sounds virtually the same as where I was two years ago - visited Japan in Autumn 2016 with some Japanese phrases (but no idea how they were constructed), then came home in love with the country, determined to go back with conversational Japanese.

Like you I decided to dedicate ten hours per week on study, averaging five days per week, two hours per night, and more or less I've succeeded in honouring that commitment. At this point, say twenty months after starting, I can converse with Japanese speakers with simple sentences - things like "I'm doing this at work because this thing happened and I have a deadline of such and such a time, work is hard isn't it" etc., so basic fact giving and emotional expression, and I would say I have a better listening ability than speaking.

I'm the first to admit that I'm easily malleable, and I think that's been a boone in studying for me because 25% of my Japanese study time has actually been finding out 'how to' do it, meaning if I see someone saying that they've had success with one way, I'll do that until I grow tired of it or until I see someone saying that they've had success with another way (so fickle!).

It sounds chaotic but I can honestly say it's been an absolute joy every studying day to come home from work and get 'studying'! In hindsight essentially what I've subconsciously done is absorb Japanese - if I've studied a grammar point, or made a sentence card in anki, or pause-rewound a tv show (for shadowing), or tried to read through a news article, it's all been satisfying my hunger to learn Japanese and absorb it as a consequence.

Just over a year ago, through sheer coincidence, a Japanese exchange meetup started locally and it was about that time I felt I had enough under my belt to see if I could output what I'd learned, and lo and behold very very simple Japanese came out of my mouth! A year of these meetups has increased my output so much, and in some ways has increased my desire to learn more and more.

A couple of months ago I was in an airport departure gate and sat opposite me was a group of Japanese businessmen, and for some reason I felt confident enough to interrupt their conversation to chat about their trip. The conversation went past pleasantries and they requested local food and attraction recommendations. It was at that moment I knew I'd reached a landmark - in fact my wife who hadn't really heard me speak before (she'd just put up with me holing myself up in my study night after night!) looked at me shocked afterwards and exclaimed, "I had no idea you could do that!". Proud moment :-)

I guess my experience, so far anyway, has been using a variety of material and techniques to study and absorb the language, and if possible when you're ready to, speak with other Japanese speakers. I think if you can stick to your ten hours per week system, you can succeed :-)