When my feelings are invalidated, when I am told how I should feel, when my words aren't truly heard.
@autumnrain22 this. This. This. It
When it's time to go to bed, and I know that I won't even get a kiss goodnight from my wife (and intimacy is out of the question).
@PassDaPuk1166 Do you do it and she doesn't reciprocate?
@softcottonpad Yes, I have tried, and I talked to her about how important it is. Nothing. Going on 4 months. I guess it only bothers me.
@Laura i am scared
When the person you thought you were closed to but they dont treat you in that way. Its when you sit alone in every afternoon after school :))
The person who hurt me is smiling and laughing while I'm all alone.
I feel lonely pretty much a nytime I have no one to talk to. AKA always
@LittleAardwolf I feel the same...
@softcottonpad
Sorry to hear that, it sucks..
When I get stuck in my head and worry.
I never know how to open up to others because I'm used to being shut down.
I feel most lonely when I see pictures of friends getting married, or already have kids (when I am still single) 
@Jaeteuk I know, same. Most of my primary and many of my secondary and tertiary class mates are already married or in serious relationships that have been lasting for years already, while I've been single since birth...
... when I am with my wife of 18 years. It's killing me.