I really find it to be a tough task to show my mother love.
What makes it so difficult for you to show love to your mother?
She manipulates me into feeling sorry for her
If you don't love your mother because she's manipulative then you shouldn't have to. Manipulative people are toxic and causes the relationship to go bad.
She's not manipulative, she just brings out the worst in me. She pushes my button.
If you do not feel natural love for your mother than it is completely fine. It can be difficult to love someone who is always bringing negative into your life. Just because someone is family does not mean you are forced to love them.