Very few, if any doctors have any idea how to get a patient off Effexor and usually recommend far too quick tapers. If you read all the posts on this forum, the most successful way to get off Effexor is to go very slowly--which means tapering by very small reductions (5-10%, or even less) and staying at each new level for quite a while (weeks, or months) before tapering again. The longer you have taken Effexor and the higher your dose, the longer your taper should take. Ping-ponging on and off Effexor every few days just puts you into withdrawal over and over again. Reducing SLOOWWWLY significantly minimizes the unpleasant (and sometimes debilitating) withdrawal effects. Tapering in just weeks can be very uncomfortable and often unsuccessful. Read why and how better to get off Effexor here–
https://www.nytimes.com/2019/03/05/health/depression-withdrawal-drugs.html.
OTC medications and supplements can help with some of the withdrawal symptoms (click on my name and read my past posts for some). Here's a good article re how to mitigate withdrawal effects with supplements (fish oil may be more helpful than krill oil; I also take GABA; do not take L-tryptophan while still on Effexor)–https://www.4mind4life.com/effexor-withdrawal-symptoms.

Ask your doctor about a "Prozac bridge"–"The only way doctors know to soften the blow when withdrawing from short half-life drugs [Effexor is such] is to add fluoxetine (Prozac). 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. You can add 20mg of Prozac to any other antidepressant and then get off the [original drug]. Once the [original drug] is gone, you can taper off the Prozac. This works because fluoxetine (Prozac) has a long half-life making it much easier to get off of than drugs like [Effexor].–https://natashatracy.com/treatment-issues/withdrawal/antidepressants-effexorpristiq-venlafaxinedesvenlafaxine/. See also https://www.depressionforums.org/forums/topic/107532-coming-off-of-effexor-with-prozac-bridge/.