You feel obligated to smile even if you feel sad sometimes because you want to hide the fact your feeling sad by smiling because smiling means you are happy. Try not to hide your sadness allow your feelings to flow and not be bottled up inside. If people are suffering from depression and you know them well try and help them the best you can and treat them the same as you would before.I had a friend that suffered from depression and she cut herself and starved herself because she felt like she was ugly and it was a hard time for me but that time is over now and she is better than she was. She now eats food, doesn't cut herself and I hope she is no longer depressed to the point of committing suicide because she was. Recently however I've been feeling this sad feeling constantly and my anxiety has me on edge much more than it did before. I now feel obligated to smile even with this feeling so no one worries about me because I don't like bringing other people into my problems. This has been going on for about 4 months now and I don't know what to do some days I am not as sad as other days and I want to know what is wrong with me. Am I being a normal teenager or not. Another thing that happened is that I went to one of the student support managers and they said to come back later so I did then they said that they would take me out of lessons so they could talk to me. It has been 5 weeks since then and they have not done anything. I just want answers on what is wrong with me 

(Sorry about that i just need to let my feeling out after bottling them up for ages)