The two main sources of negative fat thoughts are: 1. negative, destructive people who really have no clue about the power of their words, and 2. well-meaning people who simply have biases and prejudices against weight. What they say to us can only matter if we allow it to ... if we give their opinions more validity than our own.
What we allow to inhabit our minds is what will determine the quality of our lives. You've probably heard the phrase "Garbage In/Garbage Out". If you allow negativity to become the compass for where you want to go, you'll end up somewhere you don't want to be.
You have so many wonderful qualities. Start recognizing them and celebrating them. They are undeniably a part of you. Just because some people don't have the ability to see them doesn't mean they aren't there.
Have a fantastic week!