I really struggle with this 5 years in... I open my mouth when I sleep, probably because of adenoids (had them removed twice, keep growing back), so I can't us

I really struggle with this 5 years in... I open my mouth when I sleep, probably because of adenoids (had them removed twice, keep growing back), so I can't use nose pillows/masks, and the full face mask leaks badly as my bottom jaw is smaller than usual when compared to the top one. I though about chin straps, but my damn head is too big for most of them...