If I was in your situation I would spend all my free time fighting for my son.

Fuck her and her new hero fella its your child thats important and you have rights. Go to the CAB and find some legal aid. Do whatever it takes to ensure you are in your childs life. He will be the one thing that makes you smile. When all else is bad in the world your children have a way of righting those wrongs. Something simple like a smile or giggle or just saying a new word etc and your heart melts.

I would also look into the name change thing. Can she do that? Even if she can she cannot stop you seeing him!

In 18 years time, when hes grown up not knowing who is father is do you think he will give a fuck about a little money you've put aside? I wouldn't. The emotional turmoil and hatred from a kid that doesn't know their dad has no price! He will take your money, think your a cunt for not fighting for him, and run. Sorry if that sounds harsh but its the stark reality of the situation. Without being in his life you will not really mean anything to him at 18.

Fight man!!!!!!