Yep, there are people I know who managed apartment buildings or do work around the apartments in exchange for reduced/no rent. I'm pretty sure its legal! No different than getting a perk where you work like discounts or free tickets to events that you are working at.

As for the relationship stuff, I felt the same when I was that age, I didn't meet my husband until I was 27. It bugged me when people would say that I was young and to just not worry about it but they were so right. It'll happen when it is meant to happen, so for the here and now just try to enjoy life the best you can. It does sound like you have a lot on your plate stress wise, might not hurt to talk to someone to get things into perspective.