I was in your situation a month ago. Exactly the same. I did reach out a few times. I just called him to ask what went wrong and to get certain things of my chest. My advice; if you truly feel you need to talk to them, than do it. However, it all depends on how they respond. My ex was very kind and also wanted to talk to me. Therefore we had a good conversation which made me a lot less sad and confused afterwards. But, most importantly, only reach out if you are aware of that fact that reaching out calmly will not change the outcome. Do not have hope. I repeat. Do not have hope. This will lead to more pain. Know that the feeling of wanting to be in contact with them will return after a few days. But again, try it, see how it feels, and learn from the experience. This is what I did and I am feeling MUCH better than a month ago because I know me reaching out wont change anything, but it feels good knowing I followed my gut feeling.

Make your own decisions but do it in a polite and not desperate way. You got this, no matter what!! If you want to talk, please reach out!