Possible non recognition aggression

Hi this just happened a couple of minutes ago, I created this account just for this.

I have two cats. One is male. The other is female

They are both neutered/spayed.

My biggest cat Shadow, had fled out of my window, not less then 30 mins did he return. As he climbed in the window my youngest and smallest cat Lil Bit started to growl. I thought this was normal, as they would sometimes growl at each other when they were hungry. So I decided to feed them. I poured in the cat food and my smallest cat sprinted there. As my bigger cat trotted towards the bowls,Lil bit started to shriek, and growl at my biggest cat. Shadow did not react in any manner, and carried on. As Shadow turned his back Lil bit attacked Shadow. Shadow did not fight back, and instead tried to run away. Since then I have separated them and changed my clothes so that Lil bit wouldn't attack me.

 Please if you have any help please do tell me.

I live in apartment, and I would not want to get kicked out.

I would be devastated if I had to give my cat for adoption.

But I do not want to see them like this. 

Please, any help is appreciated thank you <3

It is likely Shadow encountered something on his short trip outside and got its scent on him, so Lil Bit took him as a trespasser. Once Shadow starts smelling more familiar to Lil Bit things should get back to normal.

Something about Shadow smells different and this is why Lil Bit is reacting like he is a stranger.  I had to take one of my cats the vet a few months ago and one of my cats was hissing at him when we got home.  I took the top from the pajama's I had slept in the night before and used them to pet the cat that was hissing and then pet my cat that was at the vet with them. The next time they walked past each other the hissing stopped.  My cat was not in attack mode though it was just vocalizing.  It may be a good idea to try this but keep them separated for a little while to give Lil Bit a chance to calm down.

I have 4 cats in my house and this is not unusual to see if someone goes to the vet.  It does not happen all the time but when it does I used a piece of laundry to change the scent so both cats smell the same faster. This may sound gross but I have found it to be useful.

Thank you! I just hate to see them that way! They used to do everything from grooming each other to even trying to feed each other. I will try your suggestions thanks again.