<human>: EDIT: grammar, spelling...on mobile

I've had my fair share of difficulties on the dating scene, but this one takes the cake. 

Was seeing someone [21F] that I was really interested in for the last month and a half, and it seemed like something genuine was starting to flourish (went on 4-5 dates, couple of really heavy make out sessions) but holy shit was I ever wrong.

About 2 weeks ago I got blanked for a few days so I asked her how her morning was going and she dropped a whole bunch of excuses as to why we shouldn't be seeing each other anymore, from "you're too nice, I'm a bitch, sorry this won't work out, I'm still in love with my ex boyfriend, I'm not ready to date and I can see that now." I tried to make my case without seeming too torn up (which I was), but ended up letting her go without putting up much of a fight to try and change her mind (for context about 10 back and forth texts?)

NOOOWWW today I was bored at work and took a peek at her facebook and see she is in a relationship 2 weeks after not being ready to date!!! With someone who isn't her ex boyfriend to top it off. I wouldnt've have gave a shit if she got back together with her ex, but another brand new dude? This seems to me like she WAS ready to date, and I am just a really, really, bad relationship closer.

I have had this happen to me on at least ten different occasions, where I get involved with a girl for a month, 2 months, 2 weeks then they toss me away and say shit like "I just wanted to try it out", "I don't want to date anymore", "sorry I am too busy" or I just get blanked until infinity. What the fuck am I, a human movie rental? Set me straight reddit I don't know how to approach relationships anymore because whatever I am doing now clearly doesn't work.

Can you condense the text into three sentences or less?
<bot>: Seeing a girl for a month, breaks things off after a multitude of excuses and now is dating a brand new guy. Has happened much more than once, what am I doing wrong?