I'd slowly and gently pet the fox to calm it as well, soothe it a bit
Then, I'd try to check it's temperature(don't ask how) to see if it really is sick
Next, I'd slowly wash it, and remove any potential parasites that could be on it
Then, I'd get it properly dressed(if it wishes) in cute clothing, and let it lay on my pillows
I'd then feed it some cooked chicken to moisturize and feed it, along with water
Then, I'd contact the proper authorities