My question involves child support in the State of: Florida

I was married to a woman 5 years ago. About two years after we married, we separated. I did not seek an immediate divorce as I should have and after some time my estranged wife became pregnant with twins. I have met the father of the twins and even know his name. At the time of the birth, the hospital put my name as the legal father since my estranged wife and I were still married. I was not aware of this at the time. About a year after the birth, I was served child support papers. I filled out the necessary paperwork to dispute the paternity however I learned that I was supposed to file the paperwork with the clerk of court rather than mail them in which I did. There was a court hearing to order payment of child support to the mother which I was not subponeaed for and since I was not aware of the court hearing I did not attend. At this court hearing it was ordered that I pay child support. I am now seeking to divorce my wife and I understand there is a section in the divorce papers to dispute paternity. I know I have to hire an attorney to assist in this complicated legal matter. My question is is it necessary to have DNA testing to prove I am not the father or can the mother attest in court that I am not the father? Also if DNA proves I am not the father will child support then immediately cease? The attorney I am working with has been somewhat difficult in telling me exactly what needs to be done. The mother says she is willing to comply with DNA testing however following the DNA tests, what more is needed? If the mother does not dispute the DNA tests do I absolutely need an attorney on my case or can I present the DNA results to the court along with the divorce papers myself?

THANK YOU...