The speaker says they "dine" on love, which sounds elegant, like a meal at a table. But the second image breaks that comfort. Love is a well, something deep that holds water, and instead of drinking from it, the speaker buries their teeth in it. That is an odd, even violent picture. You can't drink from a well by biting it.
The title, "Sacrifice," suggests why. Taking love seems to cost something, and the speaker's hunger comes across as a little desperate and a little painful. The teeth might be gripping out of need, or the speaker might be hurting themselves or the love itself in the act of taking it. The poem doesn't say which, and that uncertainty is part of its pull.
The mood is tense and intimate. In only three lines, the poem makes love feel both nourishing and dangerous, something you need but can't take gently.