Child related

Location: Oregon

Hello,
I just got my son back from his 5 week visitation from his bio dad. I have full custody but his dad has visitation rights. His dad lives in Texas, so he gets 5 weeks with him during the summer. My son came back and was telling my mom and I that he only ate 1 meal a day because he had to fix his own food, this child is only 9 years old. He only knew how to fix frozen burritos in the microwave, so that’s all he ate, for 5 weeks, once a day. His dad and his girlfriend never fixed him food, they would fix themselves food but not him. They would also yell at him if he was being slow or not being fully independent on everything. This isn’t the first time I’ve heard issues on visitations. I’ve got past police reports of him on a motorcycle with no helmet but his dad had a helmet, witnesses of him not feeding him on previous visitations in the past years, and so much more. What can I legally do? I dont have a lot of money for a lawyer, I’ve tried legal aid in the past and they said they couldn’t help me. But my worry for my son’s safety is getting higher. And I think my 9 year old developed depression this visitation too.