dear Lookingforpeace, excuse me as this is my first reply for about a week as I still having flu problems, so what I say may not be too clear or logical.
When we see other people walking down the street we can't assume that they aren't also suffering from what you have said, because they could well and truly ditto exactly what you are thinking, that we won't know, however it's how you feel.
It's such a good point you have made here ' I'm not alone, but then why do I still feel so lonely', oh boy this is such a strong feeling, and how absolutely true it can be, in more times than not, so is there an explanation, well yes there is, but the person thinking this wouldn't believe what is happening to them, so we have to look outside the square here.
Sometimes it doesn't matter how much support anyone has when they feel depressed, because they simply can't connect with people telling you everything from left right and centre, it all has no meaning to them, and even with your best friend trying to help you then he or she maybe well off the target in how they approach the conversation with you, although they are trying so hard to help you, but you have to remember that being in depression you could deny all the advice offered to you.
Personally when I had my breakdown, there was some much support offered to me, but I still felt all by myself, because I was dealing with issues that they didn't know about, and I wasn't ready to tell anyone, so I was all by myself, so was that my problem, well maybe but when your life has fallen into a hole, no I don't believe so.
There is a meaning and a purpose for this, but that's the hard part that we have to work out ourselves or perhaps to be slowly adviced/ helped along the way to understand what it is. Geoff.