Something you must remember is that, what you see in your mind, IS REALITY. When you affirm for a desire or picture it once, it is done. That's it. You really don't have to do anything else and it will manifest. It really is that simple.
But often times our mind may wander and we make it more difficult than it has to be. So this is where affirming and visualizing come in.
When you are affirming or visualizing, you are REMINDING yourself, it already happened, or you already have it. If you can see it or say it in your mind, it is done.
You are never "trying" to get something by affirming, you are simply reminding yourself of what you already know, you are remembering.
Do not look to the 3D world as a marker of your success or you'll always be searching and again,
"trying" to manifest something.
Instead, look inside as the marker. Do you see it? Or, can you talk about it? Can you hear it? Can you feel it?
Then it is done. Congratulations, you manifested it!
(Side note - feeling it is not a requirement, but often a byproduct of visualizing or affirming for your desire, do not force it).
You are never failing, you are never "off track". If you can see it in your mind, you have it. It's done.