@mimid0506
"Dismissive doctor" is too kind--@jakedduck1 Leonard Holloway once said about a similar response by someone else's doctor, "He’s an incompetent quack. I’d run fast and far." Often doctors underestimate the likelihood of withdrawal symptoms and overestimate the likely success of the tapering schedule they suggest--but, then they aren't the ones going through the process! The main advice on this site is go slow; in this case, your doctor pretty much has you quitting "cold turkey"--which is unpleasant at best and dangerous at worst.

Going to echo Leonard here--get to an emergency room, or a walk-in health clinic and ask for a "Prozac bridge." A doctor can soften the blow when withdrawing from a short half-life drug like Effexor by giving the patient 20mg fluoxetine (Prozac); some may need to take a second 20mg dose of Prozac.–https://natashatracy.com/treatment-issues/withdrawal/antidepressants-effexorpristiq-venlafaxinedesvenlafaxine/

Why this works--the half-life of Effexor is 5 hours and 99% of it is out of your body in one day. Prozac's half-life is 4 to 6 days and it takes 25 days for 99% of it to be out of your body. Essentially, the Prozac cushions the effect of no Effexor and lets you "ride out" the withdrawal process.