Hi there Spangles,
You may find these symptoms are your body adjusting to the reduction of the hormones you've been supplying it and the ADs also adjusting to the drop. In my experience hormones take yonks to get in and out of the system and to balance (in the longer term) anyway.
I've been on ADs in the past and found that dry mouth was a side effect anyway so it may be more pronounced now that you've reduced your hormones from your previous regime but that was just my experience.
I have found that reducing any stimulating things in your diet is helpful. For me that was cutting out caffeine in all forms, tea, coffee, cola, anything fizzy, alcohol, smokes if that's your thing and sugar. Up your intake of water too and your general exercise eg walking, cycling, swimming, yoga, tai chi etc and if poss keep or increase your social life. Anxiety can take over and be very debilitating. You may notice a difference in lifestyle can help your digestion as this can also slow with fluctuating hormones. You may be doing all these amazing things anyway!
I'd also recommend you get the best quality multivit that you can afford and check on Medscape, rxlist, drugs.com (UK database), etc for possible issues. If you want to go belt and braces there's always the British National Formulary. It's really for clinical practitioners (sp?) but the info on it is, just, wow!
W x