Hi..dont want to repeat what everyone has already said about not beating yourself up as Facebook is not WYSIWYG ( what you see is what you get).
My take on this is to understand that there are things in life you can influence and somethings you cannot and the way we differentiate and frame those things will allow us to view them differently.
Things that you can influence are your life i.e focus on your studies, career, job, health, making friends ( real ones not the social media ones) mental state.
You have the power to make your life better by focusing on those areas of your life.
If you are bored, find an activity that interests you and pursue it.
Create a 3 year/1 year plan to improve your life and relentlessly work towards it.
Somethings you cannot control or influence is stuff you see on social media which might be inaccurate and misleading, to begin with, and a waste of brain space. You cannot control how your ex is living his life but you can control how you react to it.
I call such feelings as dandruff. They live rent free on my head and only I have the power to get rid of it and till I make that decision, it will continue to bother me.
If you can disable your facebook for a while then do it. Life is so much better without it.