How much are you taking and how often? When I had first started on Suboxone my doc had me on 1 8mg tablet 2x daily. The first day that I did that, I kept falling asleep at my desk and I ended up vomiting. My doc said to cut the dosage down by a quarter until I started to not get sick. Of course, it could also be from part of the w/d because of everyone is different but it really seems like maybe you just need to find the right dosage for you. I hope you feel better!
How did you feel after you took your first 4mg dose? Did you start feeling sick after that first one or after you had taken the next dose 12hrs later?