How do I get over the fact my mum said i have no self respect?

Well maybe your mom said that in the heat of the moment and she didn't really mean it. It depends on the reason why she said that at the first place. We all makes mistakes because we are humans and that doesn't make us bad. We all deserve forgiveness. We learn from our mistakes. :3

It does not matter what your mum thinks or says..What matters is what you think about urself.. Take time to find out what you think about urself and work on that..

I recommend that you try your conscious mind to redirect into a different thought. An analogy is a horse and the rider. You are the rider and the horse is your conscious/subconscious mind. The rider gets to steer the horse in to a certain direction similar to how your mind can change your thought process. I like the book called Psychocybernetics. It reminds me that our brain is like a computer system. We input whatever data we want to. If your mom continuously say that you have no self-respect than I recommend expressing your feelings to her. For example, "I feel sad when you say I have no self respect because it's been replaying in my head. Can you please stop saying that?". If that doesn't work than I suggest finding hobbies that can help you think of it less.