<human>: Condense the text into a few key points

Background: I started dating Ashley around 5 months ago. We met at a local concert, started hanging out after it, and soon started dating. 

Within 4 months Ashley told me that she loved me, and it was clear that she was pretty into me, and was always telling me about how I'm the best guy she ever dated, and going on about how estatic she was to be with me and all that. 

I didn't feel as strongly as she did, but I really liked her and I've always been slow to develop feelings anyways. 

Anyways, one night we were drinking and chilling, and got to talking about college and somehow the conversation got to talking about past relationships. 

Eventually we kind of got into the topic of past partners and sexual history. 

Well, I found out that she slept with around 17 guys, and did other stuff with like 5 more...

I was pretty jarred to be honest, but I didn't react and kept cool and ignored it for the night. To be quite honest though, I'm not cool with her past, and decided its just best to break things off before the relationship goes further. 

So the next day, I met up with her and told her that I just wasn't really feeling it, and broke it off with her. I didn't want to tell her the real reason because I don't want her to feel bad/insecure about something she can't do anything about. 

Well, the past week shes been freaking out, obviously she started crying when  I broke up with her, but sinc ethen she's been texting me and calling me nonstop, begging me to re-consider, asking what she did wrong, and just being really upset. 

I feel really bad about all of this, and I feel really bad for her and want to make her feel better, but I don't know what to do. Should I come clean and tell her the actual reason I broke up with her?!?!?
<bot>: broke up with gf over  her past, didn't tell her real reason, she's very upset, dont know what to do.