Given that this website is not intended for issuing halachic decisions, are answers that offer no source other than "I asked my Rabbi and he said..." valid answers? What your personal rabbi tells you, without any reasoning behind it, seems to be either a useless piece of information or an attempt to tell me what I should do, neither of which seem to be productive.
Unless the question specifies a particular type of source that it's looking for, even answers that do no cite any source at all are "valid", information that comes from informal or mimetic sources is better than information with no cited source. Regardless of the type of source, the more information that the answerer can include about the source, to help readers gauge its applicability, compare it to other sources, and follow up, the better.
So, unless precluded by the question, "my rabbi" is a valid source. It's also somewhat useful because it indicates something, albeit anecdotal and difficult to verify, about the state of tradition and practice with respect to the question at hand, somewhere. The answer can be made much more useful without betraying the identity of the answerer or rabbi by including information like where the rabbi went to yeshiva, what general line of tradition the rabbi follows (e.g. Teimani, Chabad, German, etc.), and as much as possible of the rabbi's reasoning.