It was nice that your H explained what he had told your D about helping with the math.
Keep in mind that kids emotions can be just as wonky as yours (and his) in all of this. Sadly they can internalize all of this to mean it's their fault somehow. You are clearly sharp enough and strong enough to help your D with whatever comes up.
And yes, it is totally exhausting. Take care of yourself or you can't take care of anybody else.
