Lola, I always say "don't borrow sorrow from Tomorrow".
It's hard I know. But we lose so much precious time worrying for things that have not yet happened. Then we worry when they do happen. It's a double up.
Like the others have said , keep busy. If your mind goes to that dark space tell yourself STOP. Then redirect your thoughts. I find this helps me a lot. The other thing I did/do is take a sleeping pill at bedtime so I just sleep and don't follow my thoughts all night.
Finger crossed this turns out to be nothing,
Tammy

Caregiver/advocate to Husband Kris age 59@ diagnosis
DX Dec '10 SCC BOT T4aN2bM0 HPV+ve.Cisplatin x3 35 IMRT.
PET 6/11 clear.
R) level 2-4 neck dissection 8/1/11 to remove residual node - necrotic with NED
Feb '12 Ca back.. 3/8/12 total glossectomy/laryngectomy/bilat neck dissection/partial pharyngectomy etc. clear margins. All nodes negative for disease. PEG in.
March 2017 - 5 years disease free. Woohoo!