You seem to be happy with your current job, so maybe you can focus on the other things that worry you, to see if you can change them and find that part of your life that is missing. For example, if you are afraid of not having a social life in Japan, maybe you can cut back on your traveling/blogging (not a lot, just a little bit) to allow you to have more time to meet up with friends. The thing is that with social interactions it takes effort, even if you are busy you have to make the time, otherwise the time passes and you end up never joining that club/seeing that movie/going for coffee with that friend... So maybe you can divide time between your interests and social life so that each gets attention. And the more you interact socially, the more acquaintances/friends you'll make and perhaps even find someone you like in a romantic way. I know it's not easy when you are so busy, but try to devote a little time each week to do a social activity and it will grow from there :)