Have you tried the lifestyle change approach? That entails low-acid, low-fat diet, small meals, alkaline water, sleeping with head elevated, things like that. I am doing that now, tho my GI doctor mentioned surgery as an option.

This FB group offers a lot of good recipes to combat GERD: https://www.facebook.com/groups/199013402360712

This web site is from an ENT specializing in GERD/respiratory reflux. May get some ideas there: https://jamiekoufman.com/

I think there are FB groups about Nissen if you want to search for that and see what people say. There are also a few GERD support groups on FB where sometimes they talk about Nissen. Mostly they are negative stories because if you have a positive result you don't join these groups! But it's all information you can consider.

Good luck with whatever course of action you take!