Exactly.
I should clarify that when I said I have never had an anemone I wasn't saying it requires more than 10 years of experience. Rather, I wanted to convey that my husbandry knowledge on anemones would be less than others here. I am, in fact, considering an anemone for my current tank.
I think
@bhodges82 gets it just right above. The regular maintenance and husbandry parts especially. As you say, your test results are within normal parameters and there are no doubt general swings in all our tanks throughout the day/week/month/interval between water changes. There isn't a magic recipe or additive for stability but it comes through a more thorough understanding of your tank's swings in parameters. You can achieve that stability through additives, water changes, nutrient export via algae, all of the above, etc. The time aspect, especially for new reefers, is to get a handle on this ebb and flow. Someone with years of anemone experience could likely have success early on in a tank (well before the 6 months-year that is generally recommended) based on their knowledge. I don't think you or your anemone are necessarily doomed though.
If I were to suggest a course of action it would be very regular water tests and changes in the coming weeks. Be especially mindful of ammonia and nitrite which hopefully remain at 0.
Some other questions answers to which might help:
What is the other stock in the tank?
How long has everything been in there?
What size is the tank?
What kind of filtration? Skimmer?