My grandmother also was very rigid and criticised my hair. As I was full of insecurities I gave her the credit and had a very hard time. It was wasted time. The problem is not your physical appearance or your temper, the problem is them. The one who criticise others or have a harsh judgement towards others is because they didn’t grow up to a point where that accept people unconditionally. They don’t see the person, they see only parts. It’s their loss, not yours.

That doesn’t mean they don’t love you. It’s clearly something there that they have to learn or accept. They are lost. Not you.
You will be lost in the way you give credit to them.