I love this.

Well, I vow that this a lovely and sincere poem that's beautifully written. <3

Kinda cliche with words and meaning, but it was a good cliche.
Though I think that if you swapped the last three lines to be,

'I vow to be patient and true
to take you as you are

But most of all,
I vow to always love you'

I feel that would send it in a rhythm to have a nice soft ending.