Just wanted to chime in here. 35, quit nicotine (smoking, later vaping heavily) after about 20 years cold turkey.
After Day 3 I have Shingles. Currently on Day 5 and on meds now.
It was 100% brought about by the stress of going cold turkey.
This is some pretty wild pain, but it's not as bad as the mental anguish of having an active addiction.