Hello, Emito! I hope you're doing well. I'm going to break down this poem by stanza and provide some feedback for you.

The first line is incredible. This metaphor is perfect for describing relationships and how they work. I was a bit disappointed when you dropped the metaphor after the second line. In my opinion, this should be the focal point of the stanza. The rest of the lines pale in comparison to this, and you lose momentum until you get to the second stanza. My advice is to cut line 3-8 and work on fleshing out the randomness.

You begin the second stanza with another wonderful metaphor, though I would remove twisting because you've already used the verb "shutter". I shuttered line a flame is great on its own, and the addition of the new verb complicated and obfuscates it. The use of two "myself" is redundant. Take out the first one so that it reads "I believed." The third and forth line don't do anything for me and only add distance from the candle metaphor, which is where this needs to go. Consider removing them. If you don't want to remove them, flip where they go so that the candle comes immediately after at last. I would also cut some extra words and lines out, so the stanza read as such:

I shuddered like a flame
and I believed myself at last,
that I am your candle,
shining and opening your way--
but lonely in the dark hours,
silently and slowly burning.

Great piece here.