The speaker begins with a big, open declaration: they love someone without conditions, so deeply that ordinary language can't hold it. They reach for "adjectives that don't exist yet," as if every word we have is too small for the job. It's a sweet, slightly playful idea, and it makes the love feel enormous.
Then the poem turns. In the last two lines, the speaker admits they're afraid of loving this much, because the bigger the love, the more painful it would be to lose the person. The fear isn't about the other person doing anything wrong. It comes from the love itself.
The mood is tender but anxious. The poem starts warm and confident, then becomes quieter and more vulnerable. The plain, simple wording helps: it sounds like someone speaking honestly, without dressing things up. The poem suggests that deep love and fear of loss often arrive together, and the speaker can't separate them.