It all happened i think 2 weeks ago.

My friend (A) and my other friend (B) got into a fight over a stupid thing. B was trying to 'advise' A's friend about something that wasn't true but then it kind of turned into bullying(?) bc B kept basically spreading the rumors around. After that, B blamed A as the one responsible for the rumors.

From that day on B and A are ignoring each other, they are fighting.

And... I'm just between them...
Because I'm friends with A and I talk to them a lot, B thinks that i favour A over her because of no logical reason??
Morever, yesterday A and B fought again and it just made me feel incredibly sad, to be honest.

I told B and A that I'm uncomfortable being with them because all they ever talk about then they are with me is bad mouthing the other, and that I'd with they wouldn't do that.

but i think B was offended because I was trying to talk to B like normally but they totally ignored me, A seemed to be fine with it tho.

Ahhh but now I think B is upset because of me...? ahhh what do i doooo??? ;;

Friend B doesn't sound like the best person to be friends with and a little bit venomous if you don't mind me saying. You might be able to work around it if both people are very important and close to you, but fights will likely happen again and more frequently. I'd ditch B because yes that is a form of bullying, and a bit of a cruel one at that. However I'm a stranger on the internet so what would I know? heheh

Give it some more time, maybe it'll blow over. Maybe try talking to them individually and explaining how their fight is affecting you. If they're still fighting after a week or two and it's making you feel bad, then I'm afraid you'll have to stop being friends with one of them.

This seems to be similar to the situation that I am in irl

If friend B doesn't ease up on this, leave them. If things between both of them gets worse, leave both of them. It's not worth trying to be friends with people who would constantly be mean to each other.