Going on Holiday with Recent Ex?

Hi there,

i'm 26 and the girl i was dating is 26, so the low down is;

i been dating a girl for 5 months, unfortunately she does have issues in her past relationships where she has been married and been lied to and cheated on and suffers from depression from it, she gets very stressed out over the smallest of things, so anyway we have been getting on really well when we met and started to do alot of things together, went to the theatre, enjoyed dinners and generally just went out, after a month of seeing eachother we told eachother we loved one and another, things generally went "very" quick almost as fast to the point where i am now, she was interested in marrying me and hinted alot to me by sending me pictures of wedding dresses and telling my friends that i needed "get on with it" kinda thing, recently as 2 months ago we talked about moving in together.

a few times in the relationship i kinda "failed" during sex, i am not entirely sure why this was but part of it maybe was i put pressure of myself, this however made her feel insecure and "not special" as if it was her fault and not mine, it started giving her a complex and this is when things started to bubble under the service, the final straw was when she told me to record myself "having fun" to make me feel "sexy" again and before she used to like the fact what got me going with porn so i thought i would show her what i was watching, okay *bad* move i know and after that she dumped me because i was insensitive to her, now i promised that i would change but she has heard it so many times from her previous exes is that she doesnt trust me, it's kinda like her ex husband used to push her further and further seeing how far he could doit and she thinks i would of done the same but i wouldnt, i would have learnt what upset her and made her angry.

anyways, we had a holiday booked together to go visit my family in America, a dream holiday of hers... she says she loves me and still has feelings for me but it's the stressing that she went through is that she what she couldnt cope with, she said to me "i am the sweetest guy who she ever met and made her feel the most special more than anyone else ever has" she also said it wouldnt be fair because she gets stressed so easily to take it out on me as if she is scared to be with someone who loves her for herself as if she is embarrassed by it, she said too "not now but maybe in the future when you grow up abit i wont rule us out being together again" i couldnt cancel the flight to America so i asked her if she still wanted to go as friends, she agreed... is there a chance i could show her from now till then (3 weeks away) that i have changed in the sense i am sensitive to her needs, that i am mature enough for this relationship and that my head along with my heart are in with it. she still wants to be friends with me and i do want her in my life in whatever form but i am not sure what to do here?

Shall i just keep it cool and be friends and whatever happens, happens? or do i try and show her what she is missing by actually making those changes i promised to her but never did... actions speak louder than words?