I should . . . thoughts

I’ve noticed that I have dozens of small, seemingly innocuous “I should” thoughts in my head. My balance is a little shaky sometimes – I should do yoga. I read an article about antioxidants – I should eat more berries. My doctor said I need more calcium – I should drink more milk, or find a supplement. I seem to take these thoughts as facts and then use them to doubt my plan/protocol. I indulge in indecision and confusion. And ultimately I use these thoughts as excuses to give up on my plan, start over, try something else. So my question is, how do I separate fact (yoga can improve balance, blueberries have a lot of antioxidants) from shoulding myself into confusion.