I am the Executor of the Will. What do I do when one sibling is blowing up?

There are three of us. I am the youngest of the three and have taken care of mom and dad until they both passed away. It has been 18 years of care taking and taking care of their huge properties so that they could remain at home. Dad died at 91 and mom just passed this year at 97. We had just taken her out of her home and sold the home this past year before she died. My sister was the POA and took over my moms house. When the house sold none of us saw a dime of it. I am assuming from what she told me that only $30K might be left from a 90K house that sold. Mom was only in a care facility for four months before she died. At $3900 a month. She said there was so much to pay for that nothing was left. I had borrowed against the estate for 15K in 2008 when I was having such financial struggles. But I had made payments back. Not only did I pay my mom rent for several years on the family owned 40 acres, when I was not paying rent, I was paying 1/2 the taxes and doing everything for mom and all the up keep here. I am a single woman and working a full time job. I took mom to all her appts. hospital visits. On call all during the night. I mowed the lawn and took care of the mechanical things on the tractors for upkeep. I did everything. Now I have done all my duties so far as the Executor but my brother is mad because he feels I am dragging my feet and just sitting here on all property and told my sister that he wants to take the job of executor away from me. All we are waiting for is an appraiser and surveyor. We don't have to sell but he is making this a very difficult process. My stress level is over the top and we haven't been speaking for so long even before mom passed away due to his anger that he has all the time. Now he thinks my sister and I are in cahoots and planning together and has told us he is writing us off. What should I do, I cannot talk to him because he does not listen, he jumps and fly's off the handle. all the time.