I let my 5mth old watch nursery rhymes for an hour or 2, hes been watching it since he was 3mths old. I just found out that its bad!? Causing speech delays, cognitive thinking, and eye sight? Has anyone let their kids watch tv/nursery rhymes and ever had these problems?

I let him watch it because he loves it sooo much, its the only thing that will calm him from crying, and being crabby. Plus, im the only one watching him, and only one cooking/cleaning. I usually take an hr to finish cooking/cleaning. He will let sit alone and play w his toys. I feel like such a bad mother.