Plz Help My Babies(cats) Jasper and Mia

I rescued Jasper and Mia when they were 5 weeks old.they had a pretty tough first few weeks til I got their tummies settled after being feed the wrong food and having worms and fleas. They however are very tough and thrived after week 10.

So Jasper and Mia who r 5 on the 31st of July, they need their bloods done. They had a similar thing last year, but they came right after switching to a royal canin sensitivity control food.

Now the food is no longer working and their weight is plummeting again. We cant seem to find what's wrong with them. I've tried every food type wet and dry. Been told raw probably would upset their tummys. Environment factors are not the problem. They are both part ragdoll the vet thinks, and brother and sister so the vet thinks genetic but we cant do anything til we find the cause.

So they need bloods and to see the specialist vet,

They r booked in to see specialist on the 29th. This is gonna be 400 each to my knowledge. And then the bloods thru my vet was going to be 347 each so I'm kinda stressed about trying to find the money. I've managed to come up with a bit so far which will cover one kitty to the specialist and almost the 2nd one.

I've sold pretty much everything I can and am still selling anything I can. I have no family. It's just me and my 2 babies. I love my babies beyond imagining.i have PTSD from a very extreme level of abuse and they have literally saved my life.I wouldnt be without them.ive made some of the blood test money and paid for two consult fee so far plus extra for taking mia in on a Saturday.

So I asking please please can u help me save my babies. I don't know where else to go.