Welcome @ekmclean. Some people experience late or long-term side effects when tapering off medications like venlafaxine (Effexor). I moved your message to this existing discussion:
– Long term effects AFTER withdrawing from Effexor: https://connect.mayoclinic.org/discussion/long-term-effects-after-withdrawing-from-effexor/

I did this so you can read some of the previous, helpful posts and connect with supportive members like @texasduchess @jakedduck1 @secretwhitepop @mothergoose76 @sears @clutch @sharpy1946 @grammy11 and others.

Have you talked to your doctor about the symptoms you're having?

@ekmclean
Good evening,
How long did you taper off Effexor?
Although not Effexor related I had similar effects caused by low sodium. Have you had any blood tests or been evaluated by a physician since stopping Effexor? Like Colleen says withdrawal effects can happen at a later time. My belief is withdrawal symptoms are more likely to occur if taper was to quick which I suspect may be responsible since you admit you “went through hell.”
The longer you take a medication the longer it will take you body to adjust without it.
Fatigue and muscle weakness are not uncommon. I'd hightail it to the doctor if I were you.
Take care and the best of luck to you,
Jake

It’s very possible you may have something else going on completely unrelated to your withdrawal. What you’re describing sounds extreme. I would try to rule out any other illness just to be on the safe side. The Effexor may have been masking something?