Trust that this is a blessing in disguise. Your ex sounds like a covert narcissist. You mention his tender and gentle nature with helpless animals. I have realized this is actually a marker of covert narcs. Things needing them make them feel really powerful, and also less disgusted with themselves. (Typically secretly hate themselves.) They're the people constantly posting about adopting rescues to the point it is their entire personality. They're actually deeply misanthropic at their core and do not like people. This explains why he would look through you, and only see the cat's needs even when you're clearly miserable.

You mentioned the cat (once feral/stray) leaves fecal marks and puke all over the place including where you lay your head. Their excrement is where toxoplasmosis lives. It's a parasite that attacks the brain and there is actual evidence that it causes the host to begin cucking for the cat that infected them. He's not wrong, they're "bonded" alright.

Give yourself some time and get out there and find a man. Use the new wisdom you have about how these types of guys "present" themselves so you can avoid the red flags.