Took Effexor for anxiety and began "rapid cycling" - had to quit. I am not bipolar. Other options?

I've developed severe anxiety with depression as a 48 yo male. Symptoms came on quickly over a 4 month span - no previous mood disorder. My experience with Effexor and the rapid cycling has left me in very bad shape - still have severe depression and anxiety. I cycled from a euphoric high to a suicidal low every 12 hours for 5 days from just two pills. I saw a specialist who quickly determined I am not bipolar - but had a bipolar chemical response to the Effexor. Is this unusual? I am wondering what my options are medication-wise or treatment-wise. - Thanks - great website.

- John in NM