How do I go on with life never receiving apologies from people who hurt me

I’ve done this before but I don’t understand why I keep having to. I keep having horrible fallouts with people & they just move on like nothing happened & probably don’t even think about me anymore at all. The most recent thing that happened was I had a horrible breakup & my ex treated me like nothing towards the end & I will never get an apology for it. The girls that relentlessly bullied me in school haven’t said anything in years now. How do I go on accepting I will never get apologies from these people or ever talk to them again?