Cat behavioral problem?

I adopted a cat from a bad environment just 2 days ago. His name is Ted & he's almost 2 yrs old. He was caged up with 3 other cats all his life & had an eye infection since birth. I was skeptical to adopt him cos i ald hv a male cat at home & afraid they might not get along... but i couldnt stand seeing Ted in such situation. Or any animals in such situation..

The night i brought him home was a total nightmare. I had him in a 3 tier cage with food & drinks & litter box. He sprayed all over my walls & the floor. Not only that, he meows non stop. Literally.

The next morning i brought him to the vet to check on his eyes. The vet said his eye infection was so bad that now he's basically blind. It was heart breaking. So then i asked the vet is it possible to get him neutered in his condition. Vet said its possible.

So today, Ted has been castrated but the problem is.. he hasn't stopped spraying. He still meow ever so loudly & he doesn't stop for a split second. I bought Feliway hoping it helps but it doesn't seem to calm him down. Spraying wise I'm not so sure yet.

Please anyone.. if you're able to advice me. Please do..

Thank you..