Ex cheated, got the girl pregnant, stayed with me, then confessed after 4 months

The problem: Ex cheated and got the girl pregnant, di nabuo yung baby tho. Baka kaya nag stay with me. He confessed after 4 months and broke up with me all within a day. He was staying in my place, then he got so suspicious that day, need niya na daw umalis. My gut feeling is lumipat sa ibang babae or sa girl na nabuntis. But when I asked hindi daw.

What I’ve tried so far: Beg for closure and apology. Ask for the truth

What advice I need: I want them to feel my pain kasi. The only thing i could think of is, sabihin sa parents or family nila yung ginawa nila. How should i go about it? I cant sleep at night knowing they are now at peace together. Happily sleeping knowing their plan worked until the end. So i want to ruin their peace as well.