Hello Darla_luscious: I've done what you did... (twice!)

And I was on Effexor at the time. I have no proof, but I'm convinced that Effexor induces suicidality in some individuals... and I'm one. Yes, lightheadedness is absolutely to be expected in my opinion. While I was hospitalized the last time, I used a walker for a week or so before I felt steady enough on my feet to "go it alone", so to speak. So I would say that what you're experiencing is quite normal. However, it certainly can't hurt to check in with your doctor too.
I send healing thoughts your way with the hope that you will be able to find deep peace within...