Stress101, there isn't any shame in being intelligent. Side effects can mean that a medication is doing more harm than good.
While Tymlos hasn't been clinically trialed at lower doses, I'm certain that even at lower doses it is effective. If your doctor can prescribe Tymlos there isn't any known medical reason that would prevent your use of Forteo. The two medications are quite similar. Forteo is 20mcg. Tymlos is 80mcg.
My concern would be for hypercalcemia with your use of Tymlos. Are you being followed with labs? I don't think you'll need to take so much of a medication that it makes you constantly fatigued.
If you aren't taking vitamin K2-7, you might ask your doctor, though they seldom know about vitamins. Vitamin K is a hormone. K2-7 makes it easier for calcium to latch onto your bone. And makes it more difficult to latch on to soft tissue in the blood vessels and heart. I take it two hours before the injection to make sure it is circulating when all that calcium is.
Were you without symptoms at 40mcgs?