Cpap giving me bad nights

I am not sure if I have Lyme or Fibromyalgia, test negative on regular Lyme test, so several Drs think it's Fibro. Have done diets, probiotics, Lyme abx treatments, etc. Some days I have tachycardia so Dr did a home sleep test (very bad night with just 5hrs of sleep) and results said I needed a CPAP. Firs night with nose mask a disaster, it irritated my mucus lining, was bloody and with pain for almost 2 weeks; so I asked for a face mask and tried it 3 nights. 1st night just had it for 2 hrs, next night 4 and woke up several times, so I was tired all day. Last night I really tried going back to sleep with the mask after waking up because of the air pressure that is too strong, but couldn't, so I had a bad night and today I can hardly move, no stamina, a lot of fatigue. Called Dr on Monday to have the pressure changed but so far nothing, I am not using it tonight because I need a good night sleep. Has anyone experienced something similar? What can be done. I am a light sleeper.

I love astroman's suggestion. Another idea is to raise the head of your bed. Even a few inches is helpful.

Thanks for your replies, I always sleep on my side, I am able to go to sleep with the mask, but then wake up and not able to go to sleep again with it. I have tried to sleep with 2 pillows and not able, but I am going to still try it first without the mask.