Sleep Quality

I've been using my ResMed with full face mask for over a year now. For the past couple of months I've been taking off my mask after only about 2 hours of sleep. I put it on when I go to bed because I really like it to go to sleep but after a few hours I just take it off. I'll go back to sleep but wake myself up snoring a couple of times before I get up at around 8am. What to do?

If you've been using the machine for more that a year, and started taking the mask off after 2 hours for only the last couple of months, then the first question the comes to mind is "What changed?" What changed in your life conditions / sleep conditions, medication, weight and the like.
The second question, no less important is: is the therapy effective? did it become less effective recently?

See Using software to track your therapy (aka how to use OSCAR)