Funny thing is I have a pact with an ex that if either of us got the opportunity we are supposed to give messages to both our younger selves...
To us, age 19...The bad news is that you are both too young for this relationship, truly you found each other too early. But you absolutely NEED to stick with each other through this uncertainty and not feel the need to "go sow your wild oats". Sadly, both of you will end up looking back at each other as "the one that got away" and by that time too much damage and hurt will have been done on both sides to ever fully recapture what you both have right now. The few times you try will fail because of the actions you are both thinking right now. On your current paths, this relationship changes the way both of you will view every relationship that is to follow...and it will fall short every time... K- you are having issues with your dad and think the Navy is the answer...it isn't...you end up far away and miserable. Cut off from all those friends that want to do nothing but be there for you...especially D. You worry that your relationship with D leaves you too "dependant", but he is your rock and that's exactly what he wants to be, you guys make a great team when you work through things together. D, you need to let K be a head case right now, she needs to vent, be there for her and you'll get through just fine. You both think what you have is too good to be true...stop questioning your luck and just be happy with it.
And D----your guitar playing is decent, but don't quite your day job over it. Just enjoy it as a hobby. K---accept that D is a geek. Comic Books and Toy Robots are sooooo much better vices than the drugs, alcohol abuse and violence that follow with the guys who aren't D.