One thing I have found helpful instead of positive affirmations is something called A-formations. You basically ask yourself a loaded question like: Why am I so Healthy? Why am I so happy? Why do I feel so energetic? Why am I so successful in business? Why do I make so much money?
The questions force your subconcious to come up with the answers! Simple yet profound.
To get rid of negative mindsets EFT is often helpful.