Thanks for the comment I appreciate it and I will defiantly take it slower so I won't gas out so fast.
Hi Noclue, OK first watching porn and masturbating to it is ok, but not before you go to have sex with your g/f, but to much porn and masturbating to it will lead to porn enduced ED and that you dont want watching a bit of porn is good for lifting your libido and just that.
Now I think when you were sliping over to yourg/fs but not properly having sex,all you were producing was some precum, and that is why you stayed hard for long times, so when you were at the hotel for the day, and practising safe sex, you were ejeculating fully and this why you went soft, we all do, so dont fret on that bit, but doing 6/7 times a day, there will be a point when you will just stay soft, anyman would, so dont worry your just ok.
So now you can go and tell your g/f she is so lovly and shes the best thing for you and you dont want anybody else, and its just you running out of steam, so the pair of you just slow down and take it easy, try and practis more foreplay, google dobson and ross, you will find lots of ways to enjoy foreplay and more suggest you both read it, when you can.
Good Luck