Could 20mg lexapro, (escitalopram) 30mg remeron and 10mg diazepam be causing a nagging headache each day. thanks?

Seems likely: Headache can have many causes. But your combination of antidepressants certainly is a plausible cause. Remeron enhances the release of serotonin while Lexapro (escitalopram) interferes with serotonin clearance. You possibly have quite a lot of extracellular serotonin. If that is the case, then headache and elevated blood pressure can follow.

MEDICATION: Best to discuss medication with your Psychiatrist. If uncomfortable with your Dr. consult another for a second opinion. Have a physical exam by a Dr. to determine if you have a physical illness. Consult with a Clinical Psychologist for psychotherapy with ZOOM sessions. Fears and anxiety could be heightened due to the Covid-19 pandemic. Stay safe & hopeful to elevate your immune system.