Waking up with headaches

Any ideas? I wake up with horrible headaches nearly ever morning and they won’t go away no matter what I take. They go away eventually during the day, but I’ve never had headaches that got worse with sleep like this before. Former neurologist had no idea and we thought it was sinus pressure building up but ENT recently ruled that out. I can’t sleep longer than 4-5 hours without getting one.

I did read an article about high blood pressure causing headaches while sleeping, so that might be a factor, but I’ve got over a month to wait for my next doctors appointments with new ent and GP... and can’t take this any longer.

Any suggestions what I could do or take to make them stop?!