Just venting out, because I feel lost

I (F27) went through a breakup 2 months ago after a seemingly nice trip abroad with my now -ex partner. We share an apartment, because of financial convenience, which makes it even harder. I have been in the dark for these past 2 months, not knowing why the breakup happened in the first place.

I gave them time and space to process their thoughts- and recently, I brought up the topic again, asking for their reason. A heated argument followed after, scores being tallied, bargaining (mostly on my side happened). We ended up having a wordless dinner and locked ourselves up inside of our separate rooms.

The thing is, I feel immensely sad. Like my heart was given back to me and I have no idea what to do with it. It feels heavy and painful but surprisingly, this cry baby isn't crying... i just feel hollow and well a bit angry at the same time- sorry for the things that I've done and said. I also feel stupid for hoping that things could be fixed when they made it clear that- it won't. Brain refuses to process all these things and I need advice as a person who's undergoing this.