Getting over (pretty good) ex boyfriend

so i broke up w my boyfriend about 3.5 ish months ago mainly because he was sort of acting distant and i just couldn’t see myself marrying him. unfortunately, after the time apart, i realized he was a pretty good guy (compared to the rest). how do i get over him? he has a new girl (not dating yet) and has higher hopes for that relationship compared to revisiting ours (he said he likes how she has lower standards).

i have been feeling really alone recently and miss the connection and sense of familiarity/safety with him…. what can i do to get over him ??