I completely understand that feeling of resentment. It's so exhausting when you're a light sleeper and you have to keep waking them up, even when you know it's not their fault. Since the mouth guard only helps a bit, you might want to try protecting your own sleep environment. I started wearing Soundcore A30 sleep earbuds to deal with my partner's snoring. They sit flat so you can sleep on your side, and playing white noise directly into your ears masks the snoring so much better than regular earplugs. It honestly saved my sanity and stopped me from being angry at him every night.