It's completely understandable to feel nervous, especially when you're about to start the liquid diet and you've been through this process before. What stands out to me is that you lost 120 pounds and maintained that loss for three years. That is an incredible accomplishment and proof that you know how to do the work.
I can relate in a way. I had a gastric sleeve in 2021 and 2 years later had a D&S loop revision after my weight loss had stopped. Even though I had been through bariatric surgery once, I still had worries about going through the process again. It's funny how our minds can convince us that we won't be able to do something we've already successfully done before.
What helped me was focusing on one day at a time instead of the entire journey. You don't have to conquer the next two weeks today, you just have to get through tomorrow. Then the next day. Before you know it, you'll be on the other side of surgery.
The fact that you're nervous doesn't mean you can't do it. If anything, your history shows the opposite. You've already demonstrated the dedication and consistency needed to lose 120 pounds and keep it off. Those skills didn't disappear. They're still there, and you can lean on them again.
Wishing you the very best with your liquid diet, revision, and recovery. You've already proven to yourself that you can do hard things.