Your Thoughts are Powerful
Saying your thoughts are not powerful and that they have no effect on your life because you tried to manifest something and it did not work is self-deception.
Control those things that You can Control
You have no control over external circumstances or events, but you do control how you choose to respond to them. Inner peace comes not by trying to manipulate people, circumstances, or events, but by realizing the power that you have within you - the power to choose your thoughts, words, and actions.