I totally agree. I have a history of anorexia (which was probably blatantly obvious) and depression and I made the mistake of telling my co-workers and it totally bit me in the ***. I ended up leaving 5 months later. I think if my co-workers questioned me, I'd be really vague and say something like, "I had something come up, or I had a family issue I had to deal with, or if it's a daily thing; "I just prefer to work at night when it's quieter". Something like that. If my boss asked me, personally, I'd be a little more honest because you may need to take time off or need FMLA in the future, but I would still keep it as vague as possible without outright lying. I.e. "I just have a lot going on that I've been dealing with", "I had to take care of something", "I'm going through a lot right now". They will probably extrapolate what's going on, but let them do that. If that conversation ever comes up, I would also ask, "Is it okay that I come in late and stay late as long as my work gets done"? It sounds like that's okay, but at least you're being proactive then. I also struggle with depression and have a really hard time getting moving in the morning, so I totally get where you're coming from. I'm sorry you're struggling so much.