If you've been staring at a blank page for weeks, you're not lazy and you're not bad with words. You're stuck because you're trying to do two impossible things at once: remember everything you feel, and say it perfectly on the first try.
So here's your permission slip. Your vows do not need to be poetic. They do not need to be original. Nobody in that room is comparing your sentences to anyone else's. They are listening for one thing: does this sound like you talking about the person you love?
The bar is not beautiful. The bar is true and specific. "You make me laugh when I'm being dramatic about the dishwasher" beats "you are my sunshine and my moon" every single time, because only one of those could be said by you about them.
One more thing to let go of: length. Great vows are usually between one and two minutes spoken. That's roughly 150 to 300 words. You are not writing an essay. You're writing a short, honest promise.
For the rest of this course, we work in messy drafts. Messy notes are perfect. You'll never show anyone your worksheet — only the final version. So write badly on purpose, and let the good parts show up on their own.