I was speaking to one of my Personal clients yesterday, and we had a bit of a breakthrough, she finally learnt to say no. Sounds so simple doesn't it, but it's actually pretty hard.
My client, Mary we will call her. You see, Mary was forever saying yes to things in the past, like new diets etc, knowing full well she wasn't ever going to do them. But she would say yes, would start the new diet plan, would fail after a few days, and then get really down about it, and would beat herself up for weeks, and months afterwards.
She didn't realise the effects of this until yesterday, but it meant that every time she didn't complete a diet, she thought she was a failure. Now, if you tell yourself you are a failure every day, or every week, it eventually takes it toll.
Mary now says NO a lot! She knows her body, her limits and what she will be able to take on. If she isn't ready, or not sure, she says no first, then researches it properly before saying Yes or giving the final No.
Start paying attention to what you tell yourself, it all has an impact.