My girlfriend said we need to go our separate ways

Yes.

Maybe.

Yea she's saying you two have grown apart and its time for you to continue in life without being a couple and make it one your own separate ways means follow your own stuff and do your own thing without each other.

I think she means she wants to end things completely.

There is always a chance that you guys can get back together!!! No matter what!

Maybe, maybe not, it depends..she might just need her space if not then she thinks you two need to split because she doesn't think it is working or she is just getting tired of you..it can be many reasons but most of the time because she start liking you as a brother depending on how much time you spend together

Sorry, but yes.