At some point you will have to trust someone to help you, so the best person to ask is your acupuncturist who prescribed you the formulas. I can offer general information, but they know your entire case and whether or not those formulas are appropriate for you.
The licorice root (Gan Cao) in both the xiao chai hu tang and within the long dan xie gan wan is there as a harmonizer of the formula and aids the digestion and assimilation of the formula overall. In fact, if you read our [Gan Cao] page near the bottom you will see it is included in many commonly used formulas. It is not a huge amount and taken in the appropriate context it is completely fine. Keep in mind that (1) Chinese herbal medicine formulas are very often 400 to 1000 or more years old with volumes of clinical research and clinical usage accounting for them and (2) your acupuncturist has years of training in their use and possible interactions. Not that it means it is best, but the newest common patent formula in Chinese Medicine is basically at least 100 years older than any western medicine in common use today.
For the most part except for some blood thinners and in certain cases where both the formulas and the medications are trying to accomplish the same thing there are very few true negative interactions. The biggest problem over time is that people will either need less of their western medicines as progress will be slowed by their strength and control of various feedback loops, or they will need to limit their medicine as it overrides the message of the, weaker in ways, herbal medicine.
Fibromyalgia generally follows the same path as people with chronic pain and on a variety of meds. You treat them for awhile until their symptoms improve and they trust their body a bit more. You then start a somewhat lengthy in cases process of walking them off their meds which generally goes well and they get clearer and clearer during that process. And it goes that way for some length of time improving slowly but surely.
Fibro vs. pain from known degenerative causes or past traumas for example has the added benefit, however, of simply being an overdone message. You turn the message off and that's it, you limit it and that's it - you don't in many cases have to fix anything. I'm not saying it is easy, but ultimately it's just a switch.
Fibromyalgia responds extremely well to Chinese herbal medicine and acupuncture treatment. For the most part within 2-6 months you should be off of our western medicines, or at least tapering, and at some point off of the herbal medicine as well.
I would suggest you trust your practitioner, not blindly, but for more than a day or so at least. Follow their protocol and see how you do.
Stay off the internet and focus on only those things that positively shift your thinking - meditation, light exercise/walking, and/or anything else that relaxes you. If you are going to research anything spend time working on your mind and your diet. Leave everything else to your practitioners and help them, by helping yourself. If you do all of this and truly focus on shifting your mind and diet, you are not going to need them for very long anyhow.