I guess I don't understand the question, you realize you are feeding them improperly but don't want the answer to change food? Do you have a bank account? It's not difficult to set up a paypal card or get a debit going on. Or maybe a friend/family member will order for you if you ask?

Homemade mix is an option but is spendy and way more of a pain in the butt. You can't just throw a little of this and a little of that, it needs to be balanced or you will continue to have the same problem. You can try mixing in dog food, senior diets have low protien. They smell a ton worse on dog food IME though.

Most lab blocks come in 50 pound bags, you can freeze it for 6 months to a year depending on brand but the price and effect on production would be worth it even if you are wasting some. I only have about 20 breeders, plus 20 or so feeders at any given time and go through about 15 pounds a month. If there's a feed store near you (look on dealer websites to locate) they could order some in for you. I get Mazuri 6f for $23 a bag and buy 2 bags at a time, the nearest dealer to me is an hour away but it's still more cost effective to go that way.