I am 6ft 3 and my ex was about 4ft 8 so height isn't everything, or even important, we went out on halloween once dress as Dr Evil and Mini Me! If you are happy together then things like that or what others think are insignificant. As for ruining a friendship, I think if you tell her how you feel and are open and honest about it, if she says she feels the same then mission accomplished.
If not, then, perhaps it will be awkward for a short while, but then at least you will know. And you will go back to being friends quickly enough. I have been on both sides of this situation and we went back to being close, if not closer friends afterwards.
Just say it in a meaningful way and not a pressurised way that you demand her to be your girlfriend or nothing. As for the depression/cutting, I really think you need to try and convince her to seek help for both. And that is not you being shallow, it is you caring for your friend's feelings, well-being and health.
One way would be to tell her that every time she feels like cutting, go into a room and scream at the top of her voice, or hit a punch bag or something; vent her aggression in another way. But getting back to whether you should tell h "you miss 100% of the shots you don't take." There is nothing worse than regretting not doing something.
If you tell her and she is keen then you have everything you have wanted. If not, at least you will know and you can carry on being her friend, and also get some closure for yourself, helping you both to move on. And who knows, remaining friends if she initially says know, if could lead to something more if you are there for her.
Her outlook might change once she gets over the problems she has been having, which you can help her with. Good luck my friend, we have all been there, and it sounds like you are there for all the right reasons.
Don't tell her all at once. Give her hints at first. During a nice conversation drop in the line that she has beautiful eyes.
Ask her if she likes someone else. And before confessing your love, tell her you would like to have a girlfriend like her!
I cant really gove you an answer,but what I can give you is a way to a solution, that is you have to find the anglde that you relate to or peaks your interest. A good paper is one that people get drawn into because it reaches them ln some way.As for me WW11 to me, I think of the holocaust and the effect it had on the survivors, their families and those who stood by and did nothing until it was too late.