Is one daily affirmation better than one set of daily affirmations?

I think that depends. If you were my client, I would probably ask you what does loving yourself look, feel like and mean to you?

Next, I would ask you how you feel when you say, “I Love Myself” like on a believability scale of 1 to 10 (10 being it is for sure 100% self love).

Lets say you landed between a 1 or 2. Then I would ask is there another way to say it that feels more probable or more realistic. like taking a baby step toward saying and believing, “I love myself”

I would also have you do your affirmations by looking at yourself in the mirror and going through a sequence involving the mirror technique.

But whether you do only one repeated over and over or a few statements, is your choice. If you have having massive resistance to just the one statement, I would probably stick to conquering one at a time and adding statements over time.