I know where you're coming from. You sound like me.
I find my shoulder and back aches the day after I take my Beta shot. My flu stuff has gotten less but I'm struggling the next day more than ever. Tired, aches, lack of coordination, just want to crash on the sofa.
It's a tough ride most of the time. and I have to find time to fit in work and earning money!! Yikes, when is that supposed to happen??