Why am I always feeling like this?

It’s really getting tiring to always have a sad/lonely feeling inside. It’s like it’s always on my mind. I could be around a lot of people and still feel lonely and I don ‘t understand why. Last winter I went threw a little depression because I was not working and always staying home. I was crying everyday for nothing or something. But it’s been a year since but I still get a sad feeling deep inside. Especially when I think I have no one to just call whenever to talk to about everything and anything. After that depression I couldn’t stay home doing nothing I felt like I could go crazy. Even now I can’t really stay home for a long time but why? Anyone could help change that feeling. Do you thing there’s more sad people in the world than happy people ?