ANYONE... A question about LOVE!? :) :)?

So, my boyfriend and I of two years are head over heels in love with eachother. We have our ups and downs of course.. but.. some of the downs are mine to blame. Im not sure if anyone has any advice/relativity towards this... but.. i do really, really, love and care for this guy so much, there is just something about him that i cant get enough of.. and he honestly will do anything/everything for me. the thing is..... i have done some stupid/hurtful/silly/unnecessary things to him while weve been dating.. and i KNOW better than to of made those decisions/actions.. and when he asks me WHY, did you do this to me/treat me this way..... i cannot even honestly pinpoint the reason why... and i do love him and i have no idea why i would even want to hurt him like this? Why would someone hurt the person they love the most?! Does anyone know or understand what im saying? Am i just selfish and cant see straight of whats in front of me? Am i a complete F up? Do i not deserve him/anyone else now? I hate myself for this because i pushed away the only person that i ever loved and was there for me..... and i dont know how to show him that ive changed because he wont forgive me for his own protection... i hope this makes sense.. i desperately need some words of advice :)