Astrology is a matter of faith; you cannot shake the beliefs of those who have faith in it. If you do not have faith in that, then ignore it and go ahead. By choosing a life partner of your choice, you will not become a bad person or bad daughter. Remove the guilt and talk to your parents about your relationship, you may wait for proper time. You have to show your firmness and commitment towards your relationship so that they are indirectly compelled to think about that.
If you do not want to have Depression in future then try to resolve your existing guilt, overcome the tendency of holding yourself responsible for everything (which promotes guilt and thereby depression) and stop evaluating everything in spectrum of right and wrong.