Okay, I'll start message-wise:
The story is interesting, though a little confounding. Let's see... Without the aid of the title, it would be mistaken that the actual poem is not a dream. Yes, the story is fairytale-like, so obviously it is a dream, but be more descriptive. And by that, I mean, a little more informative, not just imagery. Catch my drift?
As a story it is confusing. What I got: the persona found herself in a dream/meadow, she thought it was a nightmare because she saw 'him' in a 'dark garment', so she thought he was a 'beast'; she ran, stumbled and when she opened her eyes, she saw he was not, he gave her a rose (cliche in poetry) and whispered to her.. Perhaps there's something we can learn here: do not judge quickly. To be completely honest, the idea is there, but I feel the execution was clumsy. Right now, this is just a series of events/imagery, it needs more on emotion, meaning/clarity and correction on grammar.

The title: Beautiful Nightmare. 'Beautiful' is sadly, becoming trite in poetry, but it worked in a way. I like the hint of dark atmosphere within that, plus the oxymoron.

'I could see myself
in the midst of meadow,
confused of the vastness-
encompassed me under the
silver midnight moon...'

Add articles. 'A meadow'. 'Encompassed' should be encompassing. But I think it is a wrong word choice here.

'I didn't knew him,
not even saw his face;
but, my heart woof-
with weariness while staring
the bulwark moon glittering'

First line grammatically incorrect: I didn't know him.
2nd line: I didn't even see his face.
3rd line: just confusing. 'Woof'?
'Bulwark'? I'm not even going to search its meaning, it's just un-poetic

'The quiescent night
made me precarious in
the covenant I stake
to sanguine my unshielded heart...'

Again, the word usage is just awkward. Use words that you understand.

I'm not going to quote the rest. Sorry. But this needs more work and I'm not 'in' to love poems, and I think this would suit the 'dark poems' category. I know you can do a lot better than this.
-X

The message is a little unclear to me.
Did you find love but did you think it was a beast at first?

Some words and sentences strike me as a little awkward.

I didn't know him,
not even saw his face;
but, my heart girdled-
with weariness while staring
the fortress moon glittering
in my eyes with unknown feeling...

needs work

4/5

First Xanthe said all about the mistakes xD
Yeh it is a bit messy (as u said) but I enjoyed reading alot the feeling I am not sure about it
is it love or fear or mix of both
u used many words which gave many meanings
Your tone was changing from line to line
once sad other confusing and some loving
It was really enjoyable read 5\5 keep writing =)

I am going to analyze this one. Promise.

The way I understood, it is the
fear of love, you are running from
Enjoyed reading, quite interesting and
mysterious 5/5

It was messy but despite everything thats written it keeps you reading thats what matters to me i quickly lose interest if i dont like what i am reading and i read it twice so good work keep it up mery