<human>: Could you distill the essence of the text into 1-3 sentences?

I'm a 21M and have been going out with a soon to be 20 F, in fact, her birthday is this week. Anyway, I'm already experiencing serious doubts.

When I spend time with her I do enjoy it although not as much as I feel I should.  The issue is that this girl has very low self esteem and as such is very needy which is causing me to feel smothered (on top of this I don't feel much of a connection, common interests etc.)  We share a mutual friend whose friendship I cherish and hope to preserve, I was given ample warning about messing this girl around.

We've fooled around but not actually had sex, she is a virgin and said she does want to lose it with me but is waiting to go on the pill -  this is not at all an issue for me and wouldn't make any difference.

It's gotten to the point where I get annoyed when I recieve a text from her as it is usually something putting herself down, me telling her it isn't the case and us going back and forth for ages.  

I've spoken to her about this and about her confidence issues in general and she seemed receptive at the time but still texts more than I would like - I detest texting and only really use it to organise meeting up with people and organising things.  She has refrained from putting herself down as much but our conversation still feels very weak to me.

Ultimately I cannot really see this going anywhere, especially since we both leave for college in a fortnight and will be at a distance from one another.  Ideally I'd like to be abe to break up with her without her feeling devastated and messed around by me.  

I'd broken it off before after a few days since I didn't feel ready for a relationship but came back since I didn't feel I'd given her enough of a chance (this was about a month ago)

Any ideas how I should go about this?
<bot>: How do I break up with a girl with very low self esteem without her feeling messed about because I've broken up with her before?