Questioning

I'm taking a course at Gotham Writers on writing the query letter.  Does this sound like I am questioning my decision to self-publish In Between Goodbyes?  Yes.  I read  a lot of agent's blogs.  Granted they have a vested interest in writers not self-publishing (do the math yourself) but they all discourage self-publishing.  I am looking for a publisher's view of a book that has been self-published.  Does a previous self-publish entirely negate a republication by a publisher?  Does a previous self-published book make a publisher look askance at a new book that they are being approached to publish?  Interesting research.