The hype from OD'ing on herbs and dying is extremely overblown. The herbs that are commonly used today are very safe. If you take a lot of hemlock internally, you can die. You don't ever find hemlock in any of the formulas though. The two herbs that get the most attention in terms potentially being lethal becaue of liver toxicity are chaparral and comfrey. To be clear, these fears are overblown. Both of these herbs have been used in traditional medicine for thousands, if not millions of years. There have been some questions about the safeness of these two herbs, but they have been completely vindicated. If you are having liver problems, it may be wise to take a liver protecting herb such as milk thistle seed when taking those two herbs.
Michael Moore, an outstanding herbalist, has given us a VERY CONSERVATIVE view of which herbs we need to be careful with. This is the best document that I have seen which I believe has any credibility at all. If you want to be extremely careful, use this guide in the selction of your herbs. On the less conservative side of it, you can also take the view that none of Dr. Schulze 's or Dr. Christopher's formulas have been shown to have any serious side effects. http://www.swsbm.com/ManualsMM/HerbMedContra1.pdf
With regards to your specific problems, I would suggest that each person is different. What affects one person at one level will not affect another. Let me use my Mom as an example. I'll use OTC medicines as an example. A standard aspirin dosage is two tablets. This would send my Mom into orbit. When she used to take aspirin, she would take 1/4 of a tablet and have roughly the same effect that most people have with two tablets. My mom can take 3-4 drops of cayenne tincture, but my dad comfortably takes 15 drops, with roughly the same physiological effect. We have become accustomed in our culture to think that we are all the same, but we are not. We are lead to believe that there is one optimal diet, one dosage, one correct amount of water to drink, one correct amount of exercise, one correct amount of sleep, etc. EACH PERSON IS A UNIQUE INDIVIDUAL. Sometimes you need to take the general guidance that is out there and figure out what works for you as a unique individual. When my Mom experiences overload on herbs/medicines/supplements, she backs off of everything and starts to add things back one at a time. If you have been taking the female formula for months, I suspect that is okay for you. You are taking what I would consider to be a very small dosage, at least by standard comparisons. Dr. Schulze suggest a starting dosage of 30 drops 3X a day for the female formula. But if you have found seven drops works for you, that should be fine.
I agree with Bob's point that too much, at least from a danger perspective with these herbs would be very hard to reach. You would have to drink a few bottles and the toxicity would be associated with your ability to metabolize the alcohol, not the herbs. I would also agree with Bob that cayenne is a stimulant. You may need to back off of the Brain formula to keep the stimulant out of your system and stem the anxiety.
A nervine like lobelia or Nerve formula may help calm you anxiety.
I hope this is of some help. Happy Holidays, in peace.