People forget how tiring mental health problems can be. It's hard. Really hard. I already suffer with fibromyalgia which for those that don't know is an autoimmune disease which the main symptom is chronic fatigue so I struggle enough anyway but add poor mental health in and it pushes you over the edge. I don't sleep at night and then end up sleeping for an hour or two each evening but even when I do sleep I don't feel refreshed. It's like hell. It's just a constant cycle of not sleeping and lack of energy to the point where in the mornings I feel like gravity is pulling me down to my bed and to be honest that's the same for any time I sit down.
I do try not to complain about my illnesses and you should be pretty honoured if I do because there are very few people I trust enough to talk about it with but sometimes I do just need to vent. We all do. Don't be ashamed to break down and cry when it gets tough. Don't be ashamed to say it's getting too much and don't listen when people say you shouldn't or that you're fine. If that's how you feel then it's okay to feel that way and the only way to change that is to accept it and go from there.