I don't think you should be concerned about being hooked on famotidine. I take it sometimes and don't have acid rebound when I don't take it. One can feel hyper acid at various times for various reasons and doesn't seem to be related to your weaning off nexium. So just manage it with famotidine, and you can take Tums and/or Gaviscon Advance. See what's going on that could cause it to happen now - maybe extra stress, tension. Do relaxation exercises, eat dinner early, etc... No coffee, chocolate, etc...

@benita7jay Yes, the only successful approach in my opinion is to wean yourself off it gradually. It took me over 12 months in total to get down to one tablet per week. It is only meant for short-term use for issues that are not medically extreme. I started by taking a whole tablet every second day, then eventually every third day. Then I moved to every fourth day, with an apple cider vinegar capsule on two of the days in between. Now, I still take one tablet a week as I have an esophageal stricture and I need to reduce the possibility of scar tissue forming. Occasionally, I need to chew antacids (e.g. Quick-Eze), especially after drinking alcohol. The changes that have worked for me include: dietary alterations, drinking alkaline water and taking apple cider vinegar capsules every second day.