I know a very special little 5 year old boy, whom has a VERY unfit mother. This little guy has NO biological family except for his mother. I have been taking care of him off and on his entire life, how can I gain custody of him to adopt? Without losing him in the system?

You contact CPS, and you get a lawyer, and you go to court for custody.

You absolutely will not be able to do this without a lawyer.