What is wrong with my cat?

Hi. Beginning of last week we noticed my cat could barely open his eyes and he had some strange liquid coming out of them. Then couple days later he comes back with a clogged nose with snaught and bubbles coming out. We also might think he has a fever but his body feels warm. And 3 days ago he started gagging really loudly, and this type of gagging sounds like someone is blowing their nose or dry coughing but isn't throwing anything up.. What could this be? We are really worried about him. He is a indoor/outdoor cat.

It sounds like an upper respiratory infection; he needs to be seen by a vet ASAP.

Is this why he is gagging also? It looks like he almost throws up but swallows it back.

A URI often causes gagging. He really needs to see a vet, as a severe infection can result in death.
A Guide to Feline Upper Respiratory Disease

Please take your cat to a vet and keep him 100% inside until he is well.