--Write less about yourself and your feelings about homelessness, admirable and heartfelt as they may be, and more about your subject.
--Be more informative, less hortatory
--Be concise, specific and informal.
--Remember that the best argument may be a fact.
--Provide anecdotes, information, depth and experience about the subject, not the writer.
--Read George Orwell's "Down and Out in London and Paris." Or anything else by Orwell. Spend some time not only among the homeless but as one of the homeless. Just as he did.
Glad to help,