if you went through a blindsiding breakup

I would really love to hear how you all have coped and hopefully recovered.

1 week out, 4.5 years together. we lived together, had a dog, went on vacation 2 weeks ago. had no idea he was feeling this way, never told me a thing. the points he brought up were valid, but i would've done anything and worked on myself if he just told me that the things i did bothered him. i never knew, i never had the chance to fix it. i feel guilty that my behaviour brought him to this point, but im not a mind reader. also said he wasn’t ready for an engagement. don't know how u can give up on someone like that after you have your entire life planned, after all the years of memories. without ever even communicating, it makes no sense. i decided that this was my person-we could surmount anything and i would work through anything and everything. i would've never done this to him. how can someone be so cruel? to just give up, blame you, say you’re not compatible, they’ve justified it all in their head without saying a thing to you. the blindsiding part im scared will fuck me up so much to trust someone again. just the thought of restarting from scratch is horrifying. it feels like a bad dream honestly. cherry on top are that he broke it off a week before my medical residency interviews, which i have been working toward my entire life. he knew this would crush me, and he did it during my most vulnerable moment.