I Have Been Taking Venlafaxine [Effexor] For Several Months, Twice

I have been taking Venlafaxine [Effexor] for several months, twice daily. Due to a change in our health coverage, I will not have my new member card for at least two weeks and will not be able to refill mt prescription until then. I have been told it is dangerous to miss even one dose, what can I expect as side effects when I miss so many doses. I have been diagnosed as Clinical Depression.