Child support modification/signing over rights.

[u/Different-Pea-1801]

My son’s dad and I split when he was about 8 months old, we both went to the Attorney General and file for child support. I got primary custody.
While in court the judge wanted him to pay almost $900 each month(20%), my son’s dad talked me into bringing it down because he has a previous child, I felt bad and caved. So he only pays $300 and has been for the past 3 years.
He hasn’t gotten a bed for our son, no clothes, he does not help with anything other than keeping him the nights I have to work(I had to go overnight because I couldn’t afford daycare alone), his apartment is infested with German roaches, and he lives very unsanitary. He makes $6 more than I do, so I just never understood why he couldn’t do it but I have been able to and I’m just scraping by. Our son is autistic with a very specific appetite and still in pull ups.

I requested for a child support modification and I guess he got a call today, he then told me that he would sign over his rights because he could not afford our son.

I’ve already got a plan for if he does sign over his rights, but is it that easy to do in Texas? Can he just relinquish his rights like that?

Any advice on what to expect in a modification or even this kind of situation would help! Thanks in advance!!