I have never really depended on roommates I guess. I don't understand that thought. in fact, in general in life since I have been on my own since 18 (a decade I September) far away from unsupportive family, I have realized learning how to depend on and trust in people and to set boundaries that are good for both people in relationship to be hardest. I have realized that I can get so much more out if life that way. Everyone's different but since we don't know you we have to assume something. I understand feeling people think you are incompetent and say silly things (like about laundry) if you read the pet thread I had the same problem. But I suppose some of it was my fault for not giving my details and some is everyone has different life experience. For instance, the last 5 years I have been out of school varied a lot. When I was in the middle of no where swamp land Florida where the only people my age had 3 kids and the average age was in the 50s I really would have liked a roommate. In downtown Orlando I would have liked a roommate to share expenses and have a safe person to walk back from bars with, where I am now is next to a park and near a lot of things and activities geared to my age and I am older and I enjoy living alone but I am friends with a lot of my neighbors. I don't think living alone is easier or harder nor do I think that you learn more alone, what you learn is different. I understand wanting to learn to live alone in a foreign country. I am traveling solo with or without jet around the world for a few years. I want to do what I want and don't know anyone crazy enough to do it with me. Though I know I will spend some time living with other people.
And I have mostly had good roommate experiences with people I am not friends with. Much easier. Not sure if yours was with friends or not but I had a horrible experience that way. I kind of miss roommates though so take it for what its worth. Teacher housing sounds nice. I think this is because I don't have family support, my friends have been my family for a long time. Learning to make my own ever changing family has been hardest. Knowing you are never really their actual family and that spouses and kids change everything has been hardest, especially since I am not big on long term romantic relationships. I have learned a lot sure, there certain things I could have done without learning first hand

. Its hard when there is no one there when disaster strikes. No one to check on you (locally) or who have a family to check on first, then you. Hurricanes taught me that. No dad to come and fix moldy things, or broken things. The occasional, if I die I wonder how long it would take for someone to find out gets to me, more in the past I have a strong network of friends who if they dont hear from me will probably send a search party. Plus now I don't live on ocean or in swamp. Not as scary.
I in no way think this relates to you directly, just general information that may or may not be helpful. It's just my perspective. I am also not saying living alone is bad or makes you unhappy or assuming anything about you. I grew up in the middle of nowhere (population 200 in nearest village) in Michigan and my parents worked from 5 am to 8 pm a lot so we were rather independent and we didn't get along a lot. Being raised in a city with closer family would surely give a different perspective. As would a myriad of other experiences. For instance, you working through college to support yourself is probably much different than many others. it doesn't mean their perspective is not helpful though.
Sorry this is so long, I do value getting detailed accounts of experience instead of advice. you might not. This isn't the same as experience in Japan but my experience living alone. I have lived in Michigan, florida, south Carolina, and Boston. Michigan writh family Florida with college and jobs, and the others through summer research programs at other university in provided campus housing paid by grants.