I can't do 4 more months of this

I feel like I'm losing my grasp on my life

Background: POTS symptoms that are probably related to my hypermobility. I'm doing strength training to get my chronic pain under control the but the POTS fatigue is killing me. Sleep is enough for recovery, but I keep crashing before I can brush my teeth /get ready for bed and its driving me nuts to lose such a vital part of my routine. Trying to up my water and salt intakes but it's slow going.

My cardiologist appointment isn't until Feburary. I don't know if I can keep living like this. I crash before brushing my teeth/showering/changing into pajamas 5 times a week. Sometimes I even do it before I eat dinner.

What am I supposed to do? I feel like I'm doing everything I can but it's still out of my control.