Beloved kitten's urgent healing and recovery

I took in a young kitten recently&Ive had him just long enough to really love him. Hes the sweetest thing. Just a blessing of joy. 2 days ago he was healthy happy &perfect&has become very sick very fast. He struggling to breathe&looks 100% miserable. Took him to Vet&they wanted $700 for blood work&Xrays which I didnt have. I asked if they could hydrate him with fluid&give him an amtibiotic&see if he improves thinking I could afford that. They agreed&gave him both for $233, but it hasnt helped. I feel like he could die any minute. My husband is not exactly very nice to me&this cat has been such a blessing of love&joy. Please pray for his recovery. Hes only maybe a yr old. Ive been a DogMom my whole life&never thought much of cats. Hes enlightened my life&changed that. His name is Fred (as in Flintstone). I call him my Freddy Bear&hes orange&white. Thankyou.