You might think this is coldhearted and many might not agree with me but if I were in your position knowing what I know today I would not put his name on my child’s birth certificate. I would accept that I will be raising the child alone and without any financial, emotional or physical support from an active disappearing drug addict.
I agree with this. I used to work in paternity rights and I would not put his name on the birth certificate either. The chances that he's going to actually be of help are practically nil at this point and all the birth cert would do is give him access to you and the child. I would not agree to paternity testing either unless it was court ordered - which is very unlikely to ever happen.