I was 150mg
Effexor daily for 10 months, and I knew by reading posts on here that it is a very difficult drug to withdraw from. My doctor suggested I come off it, and try life without anti depressants. It took me 10 months, but no withdrawals.
Once before I came off cold turkey, and the withdrawals lasted a few weeks. Like you say, the brain zaps are the worse.
You may wish to see how you go, and put up with these nasty withdrawals.