I need an answer as to why i received a mother who makes me feel like an outcaste? Buddhism teaches to respect parents. I do follow. But when ever i bow down our relation with my mother, she constantly tries to bring me down. She makes me feel bad for the way i look. I cannot change my skin color or my height. She nags about my appearance. My childhood was ruined and now she is making me depresses by saying no guy would like to marry me. It is getting hard to listen to her day by day. I am a person who upholds goodcharacter above anything. I can never say a bad word to anybody's face. Yet i am facing this almost everyday by my mother. When she fell ill i could not leave he and i was the one who suffer her illness more than her mentally. I feel bad as why she cannot see me as a daughter and love me when all i want is to make her happy. 
What mistake have i done in my past life to her that she is constantly taunting me to death.
What mistake have I done in my past life to her that she is constantly taunting me to death.


If you are literally asking about your past Karmas, to figure out the reason behind your current life situation, then, it is impossible for other, you yourself have to reach that level of meditative awareness to remember your past life. The ways of Karma are not linear also the ripening of fruits is also not linear, you receive the fruits when the environment is right. 

Furthermore, if you blame your past life for your present life, then you can again blame your past to past life for the deeds of past life, so the regression is infinite. So the first thing to solve the problem is that stop blaming past life or Karma or anything for that matter. The first step is to accept the situation. The first step is acceptance. 

How can you solve this problem?

From a Buddhist context, you really have two problems here, one is Attachment and other is Expectations. 

As much as I have studied human psychology I can tell you that hatred of mother for her child is usually dissociated, meaning she does not really hate you as a child but maybe she hated your father or something like that, but sometimes humans are not capable to locate the real reasons of hating somebody, so her nagging about your looks is simply her own misunderstanding of the exact thing that was bothering her about you. So the next step is to look at you mother as a human rather than 'your mother', this will free you from the attachment you have, and will be able to help you to solve the problem objectively. 

Second is you stop expecting love and affection from your mother. This expectation is same as desires, which Buddhism talks of in great detail. The suffering here is caused because you desire your mother to behave in a certain way and she is not doing it, as the Buddha said, "not getting what you want is suffering". So this is the second thing you have to learn, to drop your desire.

The next step is to learn not to react, I suggest you should do a 10 day Vipassana  retreat of S N Goenka. Here you will learn to watch the sensations without reacting to them, you will have to apply the same to your relating to your mother. So whenever she insults you, you just watch, the unpleasant sensation arising in your mind and its impermanence. Ths will help you get rid of a lot of emotional trouble. 


  she is making me depresses by saying no guy would like to marry me.


So you are depressed by her words that no guy will like to marry you. Well, you have to understand something here, if you are depressed then your mother's prophecy will be self-fulfilling because no guy will want to marry a depressed girl. So instead of feeling depressed, you fill your heart and mind with loving-kindness and compassion. If you are loving then love will come in your life, but remember the inherent unsatisfactoriness of everything. To accomplish this, I will suggest that you should also learn some Metta meditation. Ajahn Brahm is the best teacher for this, see his Youtube videos on this topic. If you could give Metta to your mother under your current situation, then you have won, girl. 

Look at the bigger picture

You take my word for this, and I assure you, that if it would not have been your mother bothering you it would have been someone else, something else. The first of the Noble truth is, There is Suffering in life. So instead of thinking that it was your bad karma that got you an undesirable mother, maybe it was your good karma that the suffering you are entitled has led you to ask important questions in life about Karma and past life. Life's plots are complicated, your mis-fortune sometimes is your greatest fortune. 

Think about the story of the Buddha, He had a perfect father, His father kept Him in utmost luxury possible, gave Him everything, but still, you can imagine His suffering that He had to leave His palace in the middle of the night, teary-eyed, to find the end of the suffering. 

So think about this, that getting a good mother or good father is also not the solution to life's suffering. Those who got have their problems. Follow the Dhamma taught by the Buddha, that's the only true way out. 

Contemplate on this story told by Ajahn Brahm and last thing I will suggest you read the book 'Who ordered this truckload of Dung' by Ajahn Brahm. Thit will change your entire perspective. 

Metta to you.