I have questions with custody/support and paternity.?

Hello. I am a single father of two beautiful children who I have custody of. My children and I went through a brutal divorce. I know, all of them are brutal. I was married for 19.5 yrs. I put my ex through nursing school while I was in the Navy. After I got off of active duty I moved back home. It was in our 5th year that we had our first child. Shortly after that I realised that my ex was having an affair. Well we separated for about 6 months. My ex wouldn't sign the divorce papers and we ended up getting back together. We got back together after we realised we were going to have a second child. Well here it is 19 yrs later and I am divorced. My ex was married less than a month later to the same doctor she had the affair with 19 years ago. I have a few questions. I live in Fl and my ex moved to NY. I am unemployed due to my ex. My ex is married to an e.r. doctor who is the director or assistant director of that er. My ex is an er nurse. Their household income has to be close to 500k. I do not receive child support. I kind of used it as leverage to get her to leave the kids. I stated that she has a chose, stay here in Fl and she would get custody or move to Ny and be with her boyfriend. She choose her boyfriend. Her exact words to the children were, "with or without you I'm leaving." I went to my attorney and stated that I wanted to ask for child support now. I'm taking on a lot for only receiving unemployment. My attorney stated that because my ex was so aggressive and has more money to piss away I should just let it go.She stated that my ex would probably just keep running up the legal fees and the those fees will probably out weigh what my children are awarded in child support. Any input on what I should do? I know it is usually best to use a lawyer but I thought child support is not something you can trade off. My ex pays for health care and the flight to Ny once a month, that's it. She doesn't buy clothes for them except while in Ny. My ex does fly down to Fl every once in a while. She does get them for the summer and we alternate holidays. Some issues that have come up lately are my ex's husband had been talking bad about the children's and my faith. We are catholic and my children go to catholic school. My son has come home stating not wanting to go to church. And the kids talked about joke that their mothers husband we saying about priests and little kids. And the next is my ex is trying to buy my daughter into wanting to move to Ny after my son graduates next years. She is stating that she would have a better life there and she could pick what ever school she wants to attend. I live in the marital home. My mother and grandmother come down and stay off and on throughout the year. So my children have a strong family structure here. Also, there has always been this question in my heart that I need to have a DNA test. What are your takes on that? I know that because the children have lived with me for more that ten years they are my children, but biologically they may not be. I would like to know and I think it could be important to them to know for health reason if they are not mine. Along those lines, after we had our second child my ex pressured me into getting a vasectomy. Is there anything I can do legally if my children are not my own and now I can't have children of my own. It has been over ten years. I know I have wrote a lot. Thank you for reading and I look forward to your advice.