Need to Hear I'm Not Crazy For Breaking Up With My Ex Girlfriend

I recently broke up with my ex girlfriend of one year. I love her very much, but our relationship had many issues. One example is that she would constantly threaten to leave. If she didn't get her way, she would say something like, "well maybe this isn't working out" or she would pack all her belongings (toothbrush, shampoo, etc.) into a bag and walk out of my apartment. This happened on a weekly basis. But at the same time, she wanted to go ring shopping three months into the relationship. She was really into the idea of getting married. She would talk about our future daughter and stuff like that.

I told her not to threaten me with a breakup every time we had a disagreement, but she couldn't stop, even after she said she would. She would often say things like, "my future husband would never." On half a dozen occasions she left my apartment in the night so that I would chase her down. It would take a while to get her back inside. Then she would want to have sex, which I always hated after having to convince her to come back inside. If we didn't she would leave again. A few times she packed my stuff up at her place and told me to leave after a minor argument.

Also, whenever I had a work trip or went to visit family/friends, she had to be there. She didn't get to go to my friend's wedding (they never met) and she gave me hell for it for like 2 weeks. Every time I go for a work trip, I'm "abandoning" her. She used that word a few times.

I know this is all bad, but when things got really rough, she promised to go to therapy and I know she made an appointment. I just feel like this is something deep that can't be changed. Can it be changed? The breakup is fresh and I wasn't 100% confident while doing it. What do I do to move forward? The idea of being alone freaks me out.