Hi, Jazz. That low spot and feeling of resignation are excruciating. I've was there in varying depths for years. Four psychiatrists, two hospital stays and about a thousand AA meetings later, I am out of that ooze and dealing with what I consider normal problems.
Giving up is OK and actually helpful if it means giving in to sound medical advice and letting go of old thought patterns.
Please look forward to your doctor appointment without too much attachment to habitual beliefs.
If anyone sees unwise stuff in my suggestions, please point it out. We all want to see you feel better.