@Hanny The main reason for breakups is cheating. The next is too much arguing and incompatibility. Guys hate arguments and drama!
Block him/unfriend him on Facebook so he can’t see all the things you post and you won’t be tempted to stalk his social media.
In the mean time, google articles and read up on proper conflict resolution.
If at any time he wants to try reconciliation, he knows how to get in touch with you..