Cool! Although I odn't know what I said to bring this on...
Am I meant to be encouraged...
...or offended?
The more of yourself you give away now, the less you'll have to give when you find that girl who you're absolutely besotted with, who you can't get off your mind, who has absolutely no flaws in your eyes, etc. etc. That's one aspect of it.
Another aspect is this: as you see/do stuff, your mind remembers it. And when you're in a committed relationship later on in your life, and you're doing stuff with your woman, those images of other women doing stuff (whether it be from porn or your own previous experiences) will come from your memory into your consciousness and you can't properly concentrate on your woman. As you keep indulging in your personal sexual habits that are outside of the relationship between you and your woman (e.g. porn, masturbation) you will see her as somewhat more of an object, and less of a human person with feelings and emotions. And that's damaging to your relationship.
I can safely say that there's a good reason that the 7th commandment says to not commit adultery. I can quote loads of scriptures regarding sexual immorality, but for the meantime I won't, except for one, where it says in Matthew 5:27-28 that anyone who stares at a woman with lust for her has already committed adultery with her in his heart.
Peace out!
Everything you just listed are PERSONAL PROBLEMS. Just because you masturbate and/or view pornography, doesn't mean any of what you just said is going to happen. I look at porn quite regularly, and I just got out of a relationship wherein I was sexually active and very much in love with her and I never thought of anyone or anything but her in the moment. I think you're screwed in the head, champ.