Are you taking any NSAIDS?
I've read a study that NSAIDS decrease the effectiveness of anti-anxiety medication.....which leads me to conclude that they may also decrease the effective of our natural well-being hormones / chemicals (ie. Serotonin etc.).
Before I read about this, I always noticed super higher anxiety levels after taking NSAIDS (my usual dose of 600mg ibuprofen).
What I found that really, really helps if this particular Rhodiola:
http://www.amazon.ca/sisu-RHODIOLA-STRESS-CAPS/dp/B00CORKXZY(I'm sure you can find them cheaper)
I find it works best for me when I take 3 capsules, ten minutes before I take my NSAIDS. (Makes a HUGE difference for me!)
I once bought 2 other different brands of Rhodiola, and they did not help at all with the anxiety. Some add ginsing or other things. Plus supposedly there are like between 36-90 different Rhodiola species (Wikipedia).
Again, for whatever reason this one is the only one I've found that works for me!
I also take it when I feel anxious (usually morning anxiety) and it really helps.
Might be worth giving them a try.