Unless you've already self-published, don't give up on getting a traditional publishing contract on this basis - it doesn't sound as if you've been correctly informed - an agent will ensure that a publishing contract only signs away _particular_ rights for a _particular_ period of time and with _particular_ provisos (e.g. if the book goes out of print the rights revert to you...) - this is why you need a good agent - and in order to get a good agent you need to ensure your novel is professionally copy edited before submitting...