Lamictal and nauseaus

I was on Lamictal 125MG at night for PTSD and anxiety for over 4 years - it took over 6 weeks to come off of it and it was very difficult - I felt sick most of the time - nauseaus, dizzy, migraine, tired, joint pain, anxious, mood swings. I have been off of it for 2 weeks now and I am still having headaches, dizziness, tired all the time, horrible dreams, difficulty sleeping and I wake up in the middle of the night gasping for air with out of control heart palpatations. I have not had night terrors in years. Is this a side effect of coming off of the medication? I learned in my research that this had not been FDA approved until I had been taking it for quite some time - is that ethical medical practice?