How can I see my son again?

I was 14 when I had my son in 2004 who is now almost 14. He has been living with his aunt, his dad's sister since he was 3. I asked her to care for him since I was not able to. I see and provide for him occasionally but he has never lived with me after 2008. In 2013, child support was suddenly put against me. I have been paying everything and even paid off back support. As of August of 2015. My son’s aunt completely cut all ties with my son and I. Everything we try to pick him up, he tells us he is not allowed. After a few attempts, I called the cops for assistance. Cops said there's nothing they can do to help me. I pay $300 a month in child support and I can't see, talk or even message my son in any way, not even my family can contact him without her permission. Is this legal? I don't mind paying the child support but it seems like there's always going to be a problem with her and wanting more money from me. I've called a few lawyers and adoption agency for help. What would be my best option? My child support case worker informed me if I got a notary to give up all my rights as my son's mom that I wouldn't be reliable for any financial needs anymore. Is this the best option for me? I would love to be in my son’s life but in this situation, I know he would chose living with her over coming back to me.