Does Skipping Venlafaxine Hcler Cause Nervousness, Ringing In Head And Emotional?

I was out of town and forgot my venlafaxine hcler I am on 75 mg cap. it has been 4 days since I have had it. I noticed I cant sleep I am nervous kinda of shaky ringing in my head and very emotional, is this a withdrawl from me forgetting this medication ? thank you Dawn