Again, if your lawyer says it's a fair aggrement, listen to that. Giving up the support will just make it harder for you and your son.

If he truly wants to change things, he can get an attorney.

You are letting him off the hook by not going back to court. As your son gets older things do not get any cheaper. You'll need to support for him.

It takes guts and skill to stand up for yourself in a reasonable (non bullying) way. Sounds to me like it's a good thing for you.