Analysis:
This quatrain by Saadi Shirazi beautifully captures the intensity of love and longing. Let's break down each line:

Line 1: سودای تو از سرم به در می‌نرود

"Your image won't leave my mind,"
The speaker is expressing that the beloved's image is constantly on their mind, they cannot forget them.

Line 2: نقشت ز برابر نظر می‌نرود

"Your form fades not from my sight."
This line further emphasizes the obsession with the beloved's physical appearance. The image is so vivid that it seems to be permanently etched in the speaker's mind.

Line 3: افسوس که در پای تو ای سرو روان

"Alas, for your sake, oh graceful cypress,"
Here, the beloved is compared to a graceful cypress tree, a symbol of beauty and elegance. The speaker expresses sorrow and regret for being so deeply in love.

Line 4: سر می‌رود و بی‌تو به سر می‌نرود

"My head spins and I cannot live without you."
The speaker is overwhelmed by love and longing. The phrase "my head spins" suggests a state of dizziness or confusion caused by intense emotions. The final line emphasizes the speaker's complete dependence on the beloved.

Deeper Meaning:

This quatrain explores the themes of love, obsession, and the pain of separation. It suggests that:

Love can be all-consuming: The speaker is so consumed by love that it affects their mental and emotional state.
The beloved is idealized: The speaker has created an idealized image of the beloved, which makes it difficult to let go.
The pain of separation is unbearable: The speaker cannot imagine a life without the beloved.

This quatrain is a powerful expression of romantic love and its accompanying pain. It highlights the intensity of human emotions and the enduring nature of love.