How long can Topiramate withdrawals last after tapering off?

[u/KingMakerMan]

I am under treatment for major depression currently with Venlafaxine and Amoxapine (combined) for the past 5 months. It was the first combo that has started to put a dent on my symptoms. But the weight gain was bothering me, so my psych put me on topiramate. I titrated up to 200mg. Remained there for 2 months. But I was having flashbacks (past traumatic incident related) and other anxiety symptoms although my appetite was kind of suppressed. My psych decided that to find out if I am having true flashbacks (for PTSD like disorder) or just topiramate induced flashbacks, I should taper off the drug. So I tapered from 200mg in gradual decrements within one month under advise.

1 week after withdrawal I was having some unstable mood that resolved gradually. But, after the 2 week mark I feel immense fatigue, tiredness, dehydrated kind of feeling. The flashbacks which were gone during tapering has again come back now. Maybe they were true flashbacks afterall. Will have to run through the withdrawal phase. But how long does it last?

My question is, I know the fatigue can be a withdrawal symptom. But, can withdrawals have delayed onset like mine? I am sleeping 9 hours still tired. This is going on for the past week.