puppy allergies frustrations

hello, sorry if this is a bit all over the place im literally sobbing as i type this. i feel so frustrated and lost, ive drained all my savings and have gone into debt trying to figure out why my puppy keeps getting yeast infections. where i live they dont offer allergy tests and there are no veterinarians that specialize in allergies either. im just so frustrated and sad because all i want is for him to get better. ive switched his food many times (yes ive been on royal canin too and other hypoallergenic puppy food), hes been on apoquel, citrizine, on medicated shampoo, gets fully blowdried after batjs, etc. still no improvement. there was only slight improvement and then it just suddenly got worse. it went from paw licking and an infection in his ears to now his eyes are swollen too. i really dont know what to do and its also been hard medicating him because he snaps at me.