Struggling to get over a break up

Hi, so my bf broke up with me a few weeks ago and it sinks in every now and then but other times in my mind to make it through the day I think we are still together... Super unhealthy ik.. it's just we had this amazing instant connection, we got along so well even with our differences, he made me feel safe and made me feel like I could do anything. I tried to be there for him the best I could and he seemed happy, we would talk about our future from me coming to stay with him this summer to us getting married.. and then one-day he just told me he doesn't feel well and it's not the right time to date me.. so I freaked out bc why doesn't he feel good like physically or mentally.. I didn't know what to do, and all he has told me is it's not physical... So now I'm worried about him but I'm also pissed bc we were planning our future and he leaves bc he doesn't feel well.. like I know he's struggling mentally and I offered to help him and I offered to find him help and I offered to give him some space for a while until he feels better but he said no he doesn't want that, that we just can't be together and I think that's what's driving me crazy is idk what happened, like why did he just wake up one-day and said nope can't do this anymore..