Non-Socialized Cats: I’m disheartened.

Hi everyone. I'm writing this long post hoping to read some happy-ending-stories from others who have gone through the same frustration and sadness as I am experiencing now.

Two months ago, I brought home a pair of beautiful kittens who are now 4 months old. The volunteer who created the Facebook post, after a long interview required to know me and my girlfriend, assured that these were affectionate cats, socialized with humans, friendly, and easy to integrate in a new home.

The reality was quite different: we discovered that we had adopted two feral cats, traumatized and kept locked in a little storage room for a week while awaiting adoption, because they were too much aggressive towards everyone. Even the vet who vaccinated them handled them roughly.
In short, these cats are terrified of humans and even aggressive. On top of that, they were in bad health, infested with parasites in their lungs: I had hard times trying to cure them.

By the time we got to know the whole story, it was too late and we couldn't imagine what the volunteer was hiding in order to get these two cats swiftly adopted. We decided too keep them: we would love them anyway, even if they wouldn’t turn out to be the "normal" cats we had dreamed of.

Over these two and half months, we’ve spent hundreds of euros on home visits from veterinarians, psychologists, and consultations with behaviorists. We’ve followed every online guide, purchased toys and all kinds of food, trying in every way to create a joyful environment and a happy life for these two innocent and scared souls.
In return, we’ve been met only with intense fear: they are roaming the house during the day, but hide as soon as they see us, other times they spend the entire day in hiding and trembling, and only come out at night to play with each other.
Occasionally, one of the sisters comes near the sofa to play with me and my partner (always from a distance), but then suddenly she turns aggressive, hissing and running away to hide somewhere.

The worst is that if someone does approach to the door (even the courier!), they have panic attacks.

Then, on New Year’s Eve, by some miracle, one of the two sisters went on our sofa, played with our wand tool and suddenly felt asleep on my legs for four hours (she wasn't even scared from fireworks!).

Everyday I wake up with this image in my mind and I feel utterly heartbroken: I live in fear of doing something wrong that will push them further away from us, but then I gather my strength and remind myself that they are innocent beings, they don't know the language of love.

Part of me says to give up because I don't feel to have the emotional strength and ability to endure such a difficult relationship in my own home: they deserve not only love, but a specialist in feral adoptions. Another part of me says that letting them go means betraying these little souls who, in their own way, have shown a bit of trust in a human despite their traumas.

I’ve spent my whole life around cats and have always been close to animals: as a child, I volunteered at a cat colony, and as a teenager, I rescued a cat from under a car who is now 16 years old and is still my best friend, he lives at my parents’ house.

Now I'm 30 and I moved in with my partner: we decided to fill our home with two kittens. Now, though, we both feel frustrated and powerless.
If I had even remotely imagined the kind of cats we were adopting, I would never have agreed. I think I’m not the right person, nor do I have the capacity or skills required to socialize such traumatized cats.
I’m also afraid to express these thoughts to my friends and acquaintances because all I get in return are superficial and negative judgments.

I also wonder why people in social media posts say things that aren’t true. If the cats have socialization issues or difficult histories, just spill it clearly! Some animals need to be entrusted to motivated and experienced people, not passed off like packages!