Help! My cats allergies are out of control!

My cat is 11 years old, had him since birth, and in the last two or so years he's developed horrible allergies. Is only during warmer seasons that it affects him. Every month the vet gives him shots to keep it under control, but lately it seems to not be helping. I'm in a bit of a financial situation and cannot get him back in until the 7th of next month. I clean his eyes daily with just warm water and he hates it. I've put antibiotic cream on the wounds per vet suggestion. Is there anything else I can do/try for him? By now it would be gone, but it never got any better since the last round of allergy shots. I cannot afford $120 every month, especially if it's not helping him. They've done blood work and fecal tests, everything was normal. He is on flea medication as well. It's only his eyes that are the issue.
A little back story on him, when he was year old some kids beat him with a bat splitting his upper and lower jaw. So he has vet little teeth and is all held together with metal rods. He also suffered some brain damage the vets think. So he isn't the easiest to treat. This is the worse his eyes have ever looked.

Your poor kitty looks so miserable.  Have you asked your vet about using an antihistamine.  I don't remember which one but one of the human ones in a much reduced dose helps kitties with seasonal allergies.

Is it possible to keep him inside with windows shut, air conditioning and an air purifier to clean pollens from the air?

Poor guy!  I would try a grain-free food and a daily antihistamine.  I give my cats 1/4 to 1/2 of a generic Claritin (Loratadine) daily during allergy season.  I add it to their wet food, add a teaspoon or so of water, crush the portion of the pill with the back of a spoon, mix together, and serve.  Start with 1/4 tablet once a day and if that doesn't help, bump it up to 1/2 tablet a day.  Be sure it's the plain Loratadine and not anything with the "D" (decongestant) in it.  If this is happening in the warmer months, he's probably allergic to grasses.

I got a hold of his old vet, the one that put his jaw back together, he went over his medical records and had me trying children's benadryl. The vet I have here didn't think it would work and wanted me to stick to the expensive shots that don't seem to be helping anymore. So, as much as he hates it and so do we, he is staying inside and we're going to give it a try. If that doesn't help any within a month he wants us to have a skin scrape done.

Thank you all for your advice, I really appreciate it. I'm so thankful his old vet was willing to look over his records and give me advice over the phone since he's an hour away and I cannot afford to go to a new vet her for at least a month.

I think is the grasses as well, since it's only warmer months. Normally we have a very cold, wet winter and we didn't last year. It's been unseasonably hot this year. Finally starting to cool down. Maybe that is why it is so bad this time around. I know the fleas are horrible. A friend cannot get rid of them on her dog and the vet said she would have to do chewable flea medication as well as every other day baths.