Loneliness? Does it struck only when you are alone?

Do you experience loneliness only when you are alone at 3 am midnight when the rest of the world is asleep and there is nobody to talk to? Well that's what the usual definition of loneliness says. But I have a different version of it. I experience it at 2 pm in the afternoon when I am surrounded with people talking to each other, not sure if they seem to be sharing their personal stuff or just random chit chats. Loneliness hits me hard at that time when I despite being surrounded by my near and dear ones still feel lonely and walk through my contact list to see with whom I can burst my loneliness to but to my surprise nobody stands out. This happens at the same time when maybe I am chatting to any random person at that point of time. I feel helpless, anxious and more often depressed. There's also a feeling of being cautious at the same time to keep my face smiling so that nobody around me notices my real struggle. It becomes a constant war to look what I am not and feel what ...