I had ME/CFS for a year or so, in which time all my friends gradually stopped keeping in touch. So I see "I've been walking alone now, for a long long time" as I've been alone for ages, "I don't want to be friends now, with the friends that just stopped by" as I don't want to be friends with people who left me when I became ill, and "I don't want to be friends, with the friends that just aren't mine" as my friends have moved on without me so I know longer know them properly, and they can't have been good friends if they deserted me.
"You've been looking, but your search will never end" as you can look forever for the perfect friends, but you'll never find them.
I had ME/CFS for a year or so, in which time all my friends gradually stopped keeping in touch. So I see "I've been walking alone now, for a long long time" as I've been alone for ages, "I don't want to be friends now, with the friends that just stopped by" as I don't want to be friends with people who left me when I became ill, and "I don't want to be friends, with the friends that just aren't mine" as my friends have moved on without me so I know longer know them properly, and they can't have been good friends if they deserted me. "You've been looking, but your search will never end" as you can look forever for the perfect friends, but you'll never find them.
But the other versions work as well.