The way I have learned to (kind of) address this problem myself is to a) try to gradually build a wider social circle and b) when I need support, put out a broad call but be specific about what I need - so like if I am having a really bad day and need somebody to talk to but I don't necessarily want them to try to fix things for me, I'll post to Facebook something like "I'm having a bad day, anybody up for listening while I vent?" And usually one or two people (and not necessarily the same people every time) will message me and say "hey! What's up?"