I'm a veteran of most ssri's. I usually tolerate very well. Just transitioning from celexa to viibryd. After several days will be increasing dose to 40'mgs over several weeks. Now at 20 mg and the nausea is horrible, pretty much all day feeling really queezy really pukey. How long should I hang in with this? How long for some sort of tolerance to build for this? Nausea is awful. Please advise.