I broke up with my GF and the ambivalence is killing me

So I had to hurry and make a message of some sort, I felt like, before I changed my mind about having any mental problems at all.

So this is how my thinking goes:
I keep going back and forth between whether I should contact my ex and make this stop, or not. But this is circular reasoning. I want to contact my ex to make the ruminations about our breakup stop.

But I also want to contact her to get help managing my Schizotypal PD, which is also something I constantly go back and forth between (I.E: "I'm just heartbroken", "I'm really sick and my psychologist is too horrible to help me, therapy has been a travesty, I'll probably end in the psych ward again, I'll never get a girlfriend again, all of my friends and family will abandon me, I'm too sick to know how to reach out for help, I'll just get worse, my career will fail, my life is going in the *******") and this leads to me wanting to contact my ex for support.

It's been three months and I've been doing exercise and making my life better by doing stuff like cooking and cleaning, but it feels like I'm just going deeper into the insanity. For example I've really been on the edge of contacting my ex.
Like yesterday when I wrote her a message and almost sent it, but then went and watched 2001: A Space Odyssey with someone in my dorm and during the movie I was ruminating about my ex incessantly, I almost couldn't stand it at the end of the movie, I wanted to go text her so badly and then when the movie ended the need just disappeared! I went into my room feeling completely at peace and in balance, went to sleep and woke up a complete mess, I.E. the above ruminations. What the hell?

What should I do?

Breakups are weird and they can change people forever.

In this case the best advice out there is this, wait and in time there will be less times of wanting to call your Ex. Although this will take a while to get over, talking to people you trust about your feelings will make the hard times easier to deal with.