Hi there, I can't officially say my name is Nikki but that is what I would like to be called please

So "Hi". I'm 21 live in the UK.
My history: ok so I haven't always known I wanted to be a woman. I would say I have definatly known something was different but this has dawned on me slowly over quite a few years.
Couple of years ago I got annoyed at myself for wanting to be a woman so I joined the army to "man myself up" and while I would never want to forget a second of my training and time there.. I just didn't fit in with the infantry, however much I loved the job. So now I'm at college studying IT.
So I have very recently decided to be totally honest with myself and just let myself hear what I was telling myself (wow this sounds crazy!) And have had to change doctors and have an appointment booked to tell my doctor how I feel, hopefully he/she (never met them yet lol) wont just laugh in my face and call me crazy.
I have a wonderful girlfriend who I haven't told any of this yet but after bringing up the topic of ->-bleeped-<- in general with her she is very open minded and we have discussed transgender issues at length but I know this is going to break her heart and I feel selfish dragging out popping her dream of a nice family of man and wife with kids with me, but I hope to all hell that we can atleast be friends.
Anyways enough of my rambling, thats me for now x