First of all, I am sorry for posting this since I am sure the same thing has been posted many many times. I have tried searching for a similar post before writing this, but I am new to the forum and got confused/lost amongst so much information/so many posts my search has returned. Also, my brain fog is getting the best of me. Of all the people in the world, I am sure you're the ones that can understand this last point

This is my second try at CPAP, so I am not a complete newbie, but the last try has failed many years ago, and although I have some basic knowledge, I am kind of starting from scratch. Last time I had a full face mask (since I am a mouth breather) and always woke up with a dry mouth in the middle of the night, and couldn't sleep unless I took my mask off. I have tried a few things for a few years but it hasn't really worked for me, so I kind of gave up and sold my CPAP in order to help pay for a custom-made mouth guard for sleep apnea, as an alternative. The mouth guard does help (I sleep better with it than without it), but it hasn't been amazing either: I still wake up feeling somewhat tired, moody and low energy, and sometimes with headache.
Dry mouth/mouth breathing has always been a problem for me, and finally this year I discovered mouth taping and it literally changed my life. My sleep improved considerably, although still not great. For a few weeks this summer I woke up feeling refreshed and energized, and I had a glimpse of what my life could actually be like, which definitely pushed me to give CPAP a try again. I believe that with mouth taping most of the issues from my first try will be solved or managed.
as a side note, I have done pretty much all I can to ensure my nose is clear to try to solve the mouth breathing issue, and although everything I have done definitely helped, only mouth taping really ensures I breath through my nose. Things I have done include: deviated septum corrected (surgery), turbinate reduction, saline rinse twice a day with pulmicort prescribed by my ENT to help with nose swelling/inflammation. I also used to have recurring sinus infections (about 4x per year), both ON and OFF CPAP (so not CPAP related) and I have undergone sinusectomy surgery to help with that, and it did help somewhat, but every now and then I still have sinus infections (probably a couple of times a year now, give or take).
So I just bought a RESMED 10 autoset, with a nose pillow mask, while also wearing the mouth guard (it helps open my airway/keep my tongue in place). I am not loving this mask, and I am considering buying a nose mask. I am open to keep trying the nose pillow, and maybe I didn't give it enough try, but I also would like to buy a nose mask and give that a try. How do I choose a good nose mask that I know will fit me alright ? I am a side sleeper if that makes a difference.
Also, as a side question: Is it normal/ok to mouth tape using a full face mask ? I imagine I'll have to get one of those too, since at some point I will have a sinus infection and I won't be able to use a nasal mask/pillow then. Reality is maybe I won't even be able to use the full face mask... when I have a sinus infection I can't bear CPAP... anyone else on the same boat of the sinus infection has any tips for this ?
Sorry, I didn't mean to tell you the story of my life, but I also wanted to make sure I included any important/relevant info, as I am sure people will suggest some of the things I have already tried.
Thanks SO SO SO much in advance for any insight you might have for me, and sorry for the long post.