The feeling of being lonely and the fear of getting judged by the people around us, makes us more introvert and more depressive, i can completely identify with your condition, as i used to feel the same as you do, hiding tears behind the smile and presenting oneself in front of others as if nothing had gone wrong with me and then avoiding help, this all used to make me cry for hours, it was worst.

But I must mention here that though that was worst but now the best part is that i have realized that, there nothing bad in being depressed and cry, but it is really bad to get addicted with depression and make the whining and complaining about the things the focus of your life. I had been a clinical depression patient and used to feel very much low, energy-less, and all the times the mood swings had made my condition so worst, then eventually i decided to leave this addiction of depression and believe when I decided this, the logical part of my mind just start working and i shifted my focus away from the dead fly clinging to the window of my room (Depression) towards the lush greenery scene on the other side of the window (My blissful life ). I just shut the door behind me and embraced my beautiful future, Make the decision and embrace the unlimited happiness.

PS: Its not any advice, its a way of making bonds with the Human beings, the social beings, that needs and deserve people around them