<human>: So my ex and I broke up in December. It was a clean break at first and we both parted ways. At first it wasnt so bad and it seems like I accepted it. Although I still loved her all this time, it just didnt hit me till february and i started to miss her terribly. I suddenly wanted her back. I tried to talk to her about us getting back together but she didn't feel the same about me anymore. If I had only said something a month sooner. She had moved on and knows what she wants in a boyfriend now. She wants to be friends of course and I did so at first, now I can't take it. The fact that she moved on so quick bothers me and theres nothing I can do about it. 
I started thinking recently and I realized what I had done wrong. Looking back, I kind of put her in second place, in her eyes. I put effort into the relationship but never enough effort I guess. I rarely went out of my way to make her feel more special because I was always busy with school, work, and so forth. 
I want to tell her this for 2 reasons: for the slim chance that I may win her back (i know shes moved on already), and to get it off my chest. Should I tell her/apologize to her? Write her a letter?

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<bot>: ex and I broke up mutually. now i miss her and i realize what i've done wrong, should I tell her/apologize for putting her in 2nd place?