Wondering Why Friends Aren't Supportive

I guess one answer people could come up with is 'they aren't your true friends anyway'. But what happens if they've been your friend for years? Like 15-20 years? Aren't those people support to stand by your side when your feeling down? I don't get it.

It's funny to me how people who you didn't even think would care, would pop up and say how are you doing? How are you feeling? Are you okay? Maybe because they truly understand what it's like to be depressed and to feel lonely, to feel emotional, to feel sad, to feel anxious. They want to make sure your not hurting yourself in anyway.

I know this just a rambling post, I guess exactly what the 'mark' is, but it's what going through my mind right now. That and I'm feeling down. Really down. I feel sad, lonely. Like I have absolutely no one around who cares and loves me. I don't want to harm myself but I just feel really upset right now. I don't understand how I can feel this lonely when I have a lovely family, mom, dad, sister, 'friends', but yet, I'm all alone. Completely. Alone. Lol like I said rambling. I just wish this would go away, I wish my medication could take This away. But what are you gunna do:/