I have low frequency hum in my head
Typical causes people hear low freq tones without obvious sources:
- Atmospheric pressure
- Blood pressure
- Brain tumor

Usually the hum appears when I go to sleep, which coincides with my usual hysterics, panic attacks or unstable angina episodes. But sometimes it happens during day.

My thoughts processes also get more and more messy and fuzzy, like if my consciousness slowly dissolves in chaos. So likely a tumor.