Getting over her

me 18m and my ex 19f of 2 years (first genuine relationship) broke up about 6 months ago and I have tried everything to get over her, but no matter how much I try it gets worse and I dont know what to do anymore like I want to let someone else into my life cause she has a boyfriend and is now getting fucked on couches at parties having trash thrown at them and apparently shes "happier now" like we didn't break up bc of anything bad js her parents hated me, so my question is how can I get over her? and is it really just sitting with it till your over it?