Fatigued

Or should I say I'm sofa king tired?
One of the things I find so dang frustrating is the ups and downs. Yesterday I felt great! Today, even though I  slept well, I am so tired.
Its been wicked hot lately . temps in the 90s every day.Today it even feels worse due to the wee little bit of rain we got. Now it's hot and humid. Blargh.
I'll take spring and fall over this any day.
My partner doesn't understand this thing... She sees it as me being lazy. :sigh: It hurts when that comes up.
My daily schedule is usually pretty full. I wake at 7am, go to my friends moms house to cook breakfast and give meds. Come home, water gardens, pull some weeds before it gets too hot. Go back to fix lunch and do chores over TW's house. Come home and do whatever needs to be done. Fix supper for all of us, pack it up and bring it over TW's house. Go back over TW's house to give bed time meds.
On the nights that I work (I work two 12 hour shifts, 7pm-7am) I still fix breakfast and supper for TW.
But I am seen as lazy.
I don't understand that.