I have seen your work in another thread, and I thought it looked pretty good. It is much better than the work of people in my area who call themselves professional.
Only you can determine if it's time to go fulltime, and it's not just about having a good portfolio. You have to weigh how much time you can invest in marketing and promoting yourself. I am not fulltime yet, but sometimes it sure feels like it. I blog actively, I use Facebook like a shameless whore, I utilize SEO, I mail brochures, I go around to local bridal shops to make new friends, make appointments, send out billing, send out albums, prints, etc, etc.
If you love doing it, and have your ducks in a row, go for it! Better now than later. :thumbup: