Howdy spaced Monkey,
Well ... I was there same place but a little older not so long ago. Replaced whilst discussing marriage. Dumped out of the blue and replaced with someone she moved in with 7 days latter.
Its so confusing or was. Taking time and being no contact helped me a lot back then. Doing what your doing removing all memories everything again a help.
Leaning on friends also helped along with family. Do you have a therapist ? It helps to have someone to talk to about BPD.
Other things ... kept busy ... yes did try drink but all it does it makes you feel worse. Being active and posting here also helped a lot.
Angry yes ... there are stages of the detatchment on the right of the page which we all go thru. Even some not there, reflect ruminate ... anger release and a few more. Some stages you get stuck on and some you go past then come back time and time again. My own bug was ruminating about the ex until I fully understood BPD and how ill she was.
You are not starting all over again, sadly she was not the right one for you and clearly did not treat you as you deserved. So knowing this and some good things and lessons we take forward and find someone special when we are ready.
A suggestion for all those things from your ex ... get rid of them. All pictures and gifts and things she left behind if they are of no real value and she will not want them back ... in the trash they go.