Can’t Stop texting BPD ex

She got diagnosed with BPD as soon as we started dating, I never did enough research on it and thought nothing of it - blinded by the love. She was everything I wanted and made me feel understood and loved.

We dated just of over 18 months and then left me out of no where. Went to concert 3 days before breaking up, sent me 5 min voice memo two days before of how much she loves me and can’t wait to move in together, celebrated our year and a half with romantic dinner and the next day dumped me.
We had plans of moving in together come January. She did everything possible to be able to see me. We would do long distance during the school year as she was in university - she drove home 5 hours almost every weekend to see me. I’m 99% positive she is already seeing someone - everything aligns with who it is etc.

So this is all so hard to accept.

We said our goodbyes after the out of the blue breakup. I received all my stuff from her in person and she didn’t even seem like the same human. She was a lot colder and she barely even cried when saying goodbye. She admitted that she would have never texted me again after the breakup. I find myself texting her looking for answers everyday how she could do this to me and leave me like this as if I never existed.

We spent every day together slept over almost every night went on family vacations together everything. It’s so hard understanding it’s over and she just moved on and I find myself texting her everyday.

How do you make yourself stop from reaching out? I know everyone is going to say retraining order etc - it is just so hard when someone who was your life made you feel loved like no one ever before just voluntarily leaves out of the blue. It is so hard.