<human>: Give me a shortened version of the text

I'm 21 and shes 20.  We've both had prior relationships each spanning approximately 2 years.  We've been dating on an off for the past year, only now getting serious about our relationship.  The major problem I have with her is her lack of communication with me and by that I mean her lack of opening up emotionally to me.  I understand that you need to give trust to gain trust and I am completely open with her about myself but she just refuses to let me in.  We've talked about the problem a lot but she just seems to be content with not letting me in.  I found out that a few days ago she spent hours venting to her best friend about all sorts of problems in her life, many of which i had no idea about.  She also has a diary she uses to vent her emotions into but I still want to be someone she trusts to talk to.  I have been attempting to break down her walls but nothing seems to work.  Any advise you can offer?
<bot>: gf has a hard time opening up her emotions to me and I would like advise on how to break down her walls