Can someone please give me some advice on what to do about my mother in law?

My mother in law is driving me crazy. I have a 10 month old son and she is like obsessed with him. She sees him once a week and is constantly complaining that I dont bring him over enough to see her. She says Im being selfish and I am constantly hurting her for "not letting her have a relationship with her grandson" She is the biggest drama queen I have ever met. She also is getting my husbands sisters to constantly call my husband (in tears) and tell him how much hes hurting his mother by keeping my son from her too much. My husband tries to explain to her that we are busy people and bringing over our son constantly is not an option, but whenever he tries to talk to her about it, she just cries and says that we are punishing her and being mean. Whenever she cries, my husband feels bad and gives in to her will. I hate it. Whenever I am without my husband, she yells at me for not letting my son see her often enough. I tell my husband about this and he underplays it thinking I am exaggerating.He confronted my MIL about this and then she yelled at me for 'talking through my husband instead of directly to her. My MIL hates me, and I know it. I cant stand her either, and would never let my son see her if werent for my husband forcing us over there every week. All she does is complain and tries to tell me how my parenting is wrong. She is trying to sell her house right now and once she does sell it, she will be moving to another state. I cannot wait, but my hopes arent that high, because the house is wayyy overpriced, in a bad neighborhood and its been on the market for 3 yrs now without any bidders. Any advice on how to deal with this dragon lady?