Why does my mother only target me and not my siblings?

Firstly I am sorry to hear of the passing of your Dad when you were such a young age, that must have been a difficult time for you and your family.  Sounds like you are in a really difficult situation and it seems unclear about why your mother only targets you.  I wonder if you are the oldest sibling, or if you have taken on a parental role to your other siblings, or had to grow up quicker as your Mum needed some support.  It may be none of the above and you may have other thoughts about why this happens that you would like to explore and understand more. 

I'm wondering if you will ever really know the answer to this, as you may not feel able to ask your Mother, she may not be able to say, or you may not be able to make sense of the reasons she gives. I wonder if you are able to speak with your siblings about your concerns.

If you are not able to fully understand, I wonder if the way to move on in a more healthy way may be to put some boundaries in place for yourself, as you can not control what others do but can control how you look after yourself. You may have already thought of this or tried this and it may not have worked.

I hear that you are doing ok in your life, and feel that your Mother can no longer hurt you in the way that she did but it still feels like things are not ideal for you. I wonder if when you see her now you are able to put some boundaries in place and communicate that you are uncomfortable with the way she behaves. It sounds like you are describing that this may be a repeated pattern as your Grandma did the same.

You may have considered therapy or had therapy before, I feel that it could be a helpful place to explore this situation, so that you can begin to understand it more and move on in a way that feels more positive for you. You may also want to consider using a journal to process your thoughts or talk to a trusted friend.

Take Care.