I would ask yourself a few things before spending any money. And also think about what you want to do. These would be the steps I would ask myself.
1. Is your system bright sound set up or too analytical?
2. How is your health condition? Tired body or low immune condition can also cause fatigue in hearing. Have some rest and try again, if this is the case.
3. If you are already happy with your components, you need to think about which component you are willing to change.
- speakers? too bright? too analytical?
- if you are streaming, Tube output DACs are easier on your ears.
- Power amps, try warm tone tube amps, if you are using class D amps.