Struggling with Chronic Fatigue

I’m so tired all the time and it’s like every cell in my body is tired. I don’t see any correlation between my activity and fatigue. Just most days I’m unproductive, brain fog, tired eyes and frustration over not being able to just do the things. I got diagnosed with CF and didn’t really connect with the doctor so I just haven’t gone back or found a new one and it’s been years. I kinda feel like I’m just lazy and that the CF is not a real thing.