This isn't the sort of suffering you may experience after breaking up with your girlfriend. The kind of pain we sense in "We Wear the Mask" comes when the speaker's whole world appears cold and indifferent, and there's not much support around to help him. Adding insult to injury is the fact that it's awfully dangerous to even talk about this sort of thing. But there's also hope that all of this suffering could be abated in due time. Luckily, in the time since this poem was written, it has been for many people.
Misery loves company, right? The speaker isn't suffering alone in Dunbar's poem, which makes the problems he refers to all the more salient.
No. In fact, misery does not love company. (We don't know where we got that idea.) Everyone suffers alone, so even if Dunbar's speaker appears to represent a larger group, his pain is still his own.