Have you been checking your blood pressure? Mine dropped to low 80s/lo 50s (my normal was low100s/mid60s), which made me very fatigued all day long, even though I injected before bedtime. Lots of time I had to lie down to feel comfortable. The thing helped I think was lot of water (10-12 cups throughout the day) and adding salt when needed. After one and half months or so I felt totally normal. I guess I was lucky not having any other symptoms.

You probably know forteo is known to increase blood calcium transiently. My blood calcium was increased to 10.5 for a few months then went down afterwards. Recently I switched to AM injection and noticed blood calcium would increase within a few hours of injection. The high calcium level didn't cause any symptoms for me though.

Headache and insomnia could be side effects, but they don't appear to be remarkably increased (insomnia slightly increased) compared to non-forteo treated population according to package
insert. I think it could be serious when blood pressure gets too low. Dizziness could occur, and syncope if it occurs, could be very serious.

Every other day dosing seems a very good idea. If all your symptoms occurred only after starting of forteo, and they persists, that will be concerning.

Best wishes