Hi Beccy,
I'm sorry that you're going through a difficult time. A r/s break-up with an ex with a personality disorder is like no other break-up. It helps to grieve the loss of the r/s, it also helps to see a T ( you're doing that ) and talk to a support group concurrently. You're not alone.
I'd like to echo Meili, it helps to connect with people that love you unconditionally and self care is important. What do you like to do for self care?