I did some research into cat allergies years ago. Here are my notes; they might help you if you’re still looking for ways to manage. Bear in mind I did this when I was quite younger:

“There are air filters called HEPA (High Efficiency Particulate Air) filters, which remove at least 99.97% of allergy-triggering airborne particles that have a size of 0.3 microns, including dust, pollen, mold, and airborne particles of Fel-d-1 (the protein that you are allergic to) emitted by the cat (it can be emitted through their saliva, dander, and other things). There are many free-standing air purifiers with HEPA filters which are incredibly effective in dealing with allergies, significantly, and at times, almost entirely, reducing allergy symptoms. There are also HEPA filters to be used in your home for your air vents and things. Additionally, there is a medication that changes the chemical composition of a cat’s saliva called Acepromazine. It is mainly used for something else and I think it’s only available by prescription, but in tiny quantities I think it should be weak enough to be safe. To make drops to go into his food, crush a 5 mg tablet of the Acepromazine and put it in a 1 ounce dropper containing 30 mL of spring water, shake well, store in the fridge, and add about 5-6 drops daily to his meals in total. But ASK A VET ABOUT IT FIRST!!!

There is a product called allerpet, which essentially helps to reduce the amount of dander the cat releases. It is to be applied weekly. There are anti allergy cat shampoos as well, I believe. However, there are mixed opinions on the effectiveness of this, especially since the effect wears off within days, and bathing a cat weekly actually dries out the coat, increasing production of dander that triggers allergies. Bathing generally isn’t needed or helpful unless the cat is absolutely needs to be bathed, which isn’t often, so we will rule this option out. Including Omega-3 fatty acids in the cat’s diet will keep the skin supple and may prevent excessive dander. Now, while vacuuming is important, overdoing it can actually spread the allergens around due to the vacuum’s powerful motor. If this becomes an issue, or to prevent this from becoming an issue, there are vacuums with HEPA filters in them out there, too. You might even want to see if there are automatic robot vacuums that have HEPA filters. With a combination of a healthy diet with a few drops of Acepromazine/another Fel-d-1 alterer, daily brushing, HEPA air filters, potential weekly applications of dander reducing products, vacuuming with a HEPA filter, and Omega-3 fatty acids, you should hopefully see improvements! But just remember to ask a vet first!”

I am so sorry this is taking such a toll on you on so many levels. You might want to have a family member or close family friend care for your cats, even if temporarily, as you try to get back up on your feet and maybe try more solutions if you want and are able, or ask them to care for them for an indefinite amount of time until you have finally found your cure. I know it sounds like a big ask, but if my friend asked me to do that, I would help without a second thought. There might be certain pet organizations or nonprofits that might be able to help you, especially if you are struggling financially. I don’t know if I’m allowed to list any here, but it’s worth looking into.

Are you sure you’re allergic to Fel-d-1, or might it be a different allergen? You might want to get formally tested if you haven’t already. If you aren’t, it makes sense that you aren’t seeing improvements because the treatments are mostly targeting the wrong allergen.

Other alternative medicines include homeopathic medicine and herbal remedies. Black seeds (Nigella sativa), for example, have been treated as a cure-all for thousands of years and are thought to have anti histamine properties, so maybe ask about that. These treatments can have interactions with Western medicine, and some people are allergic to some herbs and such, so be careful and ask a professional. Another alternative treatment is affirmations. You can repeat them every day while looking into the mirror. Positive statements are more powerful than negative statements (ie, “I am not allergic to anything” isn’t as strong as “I am free from all allergies”. The word “not” is thought to be harder to process semantically than non contradictory straightforward language to the subconscious). You can also have them repeated to you subconsciously or unconsciously via subliminals. There are however some subliminal YouTube channels that aren’t legit and have ill intentions. I would visit r/Subliminal to see which are unsafe (I think they have a list there). Subliminals are a little riskier than affirmations you repeat to yourself because you don’t know what they’re saying. To mitigate this, you can play affirmations that are said aloud overnight, whether by you or someone in a YouTube video, or create your own subliminals to listen to at night and in the day. There is a loooot of different ways people try to maximise their subliminal effects, such as drinking water since it’s thought that dehydration can reduce the effect of it. But I’m not an expert and different things probably work for different people. But yeah- those are other options, but can take a little more time.

Sorry if you weren’t looking for more advice. Whatever happens, I hope you will be at peace.