<human>: Can you give me the gist of the text in a nutshell?

i've never felt this low in my entire life. We had our problems recently but I never thought it would come to this, and especially not this sudden. 

She can't give me a solid reason other than 'you said it before me' in an argument roughly 2 months ago I said I didn't like her. We made up literally the next day. She's been at uni for less than a month. I know for a fact this is an excuse and it's making me feel so much worse, I feel like she's been planning it for a long time and she just used me until she started her new life, found new friends and started meeting other boys. 

It's making me question myself as a person and what I did wrong for her to lose interest so quickly and be so cold about it, am I *that* horrible of a person? she is so unapologetic and hostile and keeps using the same excuse. It's almost like she's speaking from a script which is honestly the most upsetting part as my brain is now going overcharge thinking about every possible reason 

I don't really know why I'm posting this, I'm super depressed at the minute and need a second opinion and I have no one else to talk to about this stuff, I think I may go and see my psyche again.
<bot>: my girlfriend says she doesn't love me but refuses to give a reason other than a more or less cold hearted 'you started it'. Need advice.