Nothing can be done legally, and taking revenge is also bad. It might give you a short boost however will not last.
If you want to talk, I am all ears.
Always remember, people (gf/bf/friends) are a part of our part so if we keep it that way things are a bit easier.
However if you make them your world a situation like this happens.
I know it is easier said than done but you need to build yourself again.