Welcome to health care magic
I can understand your situation. I appreciate your effort to seek online support.
Your symptoms points towards the probability of "anxiety disorder". Caffeine intake can worsen anxiety symptoms. Twitching could also be related to that.
Smelling metal needs ENT check up once to rule out any other pathology.
Following treatment strategies would be helpful-
1) Antidepressants like SSRIs (escitalopram, sertarline, paroxetine etc)
2) Antianxiety agents
like clonazepam, lorazepam, alprazolam etc
3) Psychotherapy/ Counselling
4) Relaxation techniques
like yoga, meditation
, deep breathing etc
5) Avoid tea, coffee and take proper rest.
Hope it helps
Dr. Gourav Monga