I would have to agree with Paxil. There are definitely no magic pills in treating this. For me, the most important step in dealing with anxiety is gaining the knowledge to understand and confront it. Talk therapy worked wonders for me and gave me the tools to deal with it.
My own two cents worth is that if your anxiety is diminishing I wouldn't get into benzos. That occasional taking the edge off can increase. What you seem to be having is a problem with your treatment. Again, my own two cents worth, is that I'd look into natural treatments, exercise, meditation, yoga, all that sort of thing given that you don't seem to be as affected by your mood problems as by your hormonal problems, and Xanax won't do anything about that. There are plant and amino acid based relaxants that might be enough to take the edge off without getting into the serious meds that those of us who have severe anxiety problems take but wish we didn't have to. If you do go with the Xanax, exercise great discipline not to take it often, but again, if you don't need it often, I don't think you need it at all. There are no magic pills out there, and once you start on these meds, you can develop that need which is now just a want. But again, you have two others whose opinions might be worth three cents to my two.
If your doctor prescribed it to you for use then it can be used on an as needed basis. Most times doctors prescribe it to you is 'as needed.' Xanax is a short acting benzo; potent with a short half life which is prescribed for anxiety. As with any benzo, tolerance and dependence can build, but if you are not taking it on a regular basis, then it should not be as much of a problem if you were taking it every day for a prolonged period of time in my opinion.
Xanax is intended to be taken on an "as needed" basis, so I feel this is fine. But it sounds like you have more of a depression problem going on according to your symptoms. Hormones wreak havoc with our emotions as well, so it would be best to speak with a psychiatrist so you two can sort thru all this and figure out what is what. Good luck and take care!