Chin Strap for CPAP Users - Adjustable Mask Bandage Keeping Mouth Closed - Better Night's Sleep Anti Snoring Chin Strap for Snoring for Men and Women (Black)

Definitely call or stop into your sleep clinic. You shouldn't be experiencing this much discomfort. It sounds like your mouth is opening while you sleep, hence the dry mouth and sore throat. The air will just whoosh through you and dry everything out. You might benefit from wearing a soft chinstrap (this is one I found on Amazon that's cheap and has good reviews), or perhaps a different kind of mask that covers your mouth as well. I don't do well with full-face masks, myself, but they do make styles that are less clunky than they used to be. There is often a bit of an adjustment period when getting into CPAP therapy, but it shouldn't be this rough on you, imo. I hope you can get things figured out and get good rest soon.