Welcome to the GERD forum! At four weeks post-op, you're at the infancy of your recovery. It takes a full 6 months for most of the healing and a full year for the rest. I found improvement into the second year, believe it or not!
Your stomach has been through a lot, and and some will react with nausea. Often surgeons will continue to recommend that their patients continue with PPIs to help reduce some of the stress on the healing stomach. You might call your surgeon or GI doc and see if he/she things this would be helpful. I know it was helpful in my case.
Hang in there! This will get better as healing continues.
Words of wisdom by Eckhart Tolle:
"Whatever you fight, you strengthen, and what you resist, persists.”
“Worry pretends to be necessary but serves no useful purpose”
“Accept - then act. Whatever the present moment contains, accept it as if you had chosen it. Always work with it, not against it.”