I'm in a bit of a pickle

So I have a female cousin who I am very close to, we are almost like friends more than just sisters.

She has had a male best friend for the past 4-5 years. They have always been mostly online friends and only met once or twice.

Recently I moved to the city that they both live in because of college.

Her best friend and I have never been in any relationship our whole lives. So she thought it was a good idea for all of us to get together because she wanted to be a matchmaker for us two.

And so we did. We met and liked each other and now we have been dating for almost 5 months.

But the day we met, all three of us sort of had a fall out and now she's gotten a lil distant from us. I still see her and approach her to try and do stuff we did before all of this. Also she broke up with her boyfriend around 2-3 months after we met and now she's single so I feel even more guilty about her not being as close as she was with her bestfriend before that night.

But those two barely talk anymore. They have both told me on multiple occasions it's not my fault but I keep on feeling guilty and thinking somehow it is. I don't wanna get in between them but I also don't know what to do or feel about it.

Do u think I should try to make them talk more to each or let them handle it like they want to ?

Do u think it is my fault? Should I be feeling guilty?