uh.. i'm not a psychiatrist
but we can look at dreams like how we can look at poems. There is no real answer, but there are many variations and rationales.
Now, I'm only speculating and taking a wide stab in the dark here, but this is what I think.
Try not to delve too much into what I say
I'm walking through a dark hallway and I can see a light at the end shinning
This could be your present life. The dark hallways is what your life is now. Somehow you feel trapped in an unknown; unsure of what is going on around you.
The light at the end is what you perceive as your future. You want your future to be bright and open. A complete change of what youre experiencing now.
I get closer and I figure out its a dark haired girl sitting with her back to me.
This girl could be something you're aiming for in the future. Her "back to me" position may indicate that there is some mystery around what you desire in the future.
I can see she's shaking. I ask if she's alright. She turns to me and she's the most beautiful woman I've ever seen. She's slightly weeping and shaking.
The girl is weeping, shaking, heartbroken (?). Maybe. This could indicate that within your desired 'happy bright' future, there is something or someone who is going to give you that piece of sadness and sorrow.
She then gets up and briskly walks towards me and hugs me tightly. She continues to cry and I hold her gently, reassuring her that it'll be okay.
You're ready to embrace the fact there is going to be that sadness in your future, and willing to deal with it and find comfort.
She then leads me down to sit with her, she's still holding me. She stops crying and says, "I've always loved you." and then she crumbles to ash in my arms.
This troubled me a bit. There could be 2 things behind this part.
a) Despite your readiness to take control of what is to come, you fear that you will eventually be faced with utter disappointment.
b) After overcoming your sorrow, you seek some kind of reassurance that this 'future goal' still 'loves you', and that it has not given up on you(?) or something.
The crumbling into ash part could show your willingness to let go.
I hope this helps.
