Healing after being rejected by mother, even after diagnosis

I don't even know where to begin. I'll make a long, painful story as short as possible. In 2012, my mother's mother passed away and shortly thereafter, my mother began to fall apart. She had always been a loose cannon emotionally, never affectionate toward me (but highly toward my brothers and sister), and never interested in getting to "know" me. I was 2nd born, first to my father. There was immediate resentment from my sister because of that. I fought tooth and nail to get Mom's attention, to feel like she even liked me. Even as an adult, she was difficult to have a conversation with as it always pertained to her or how people were trying to sabotage or screw her over. But after her mother died, she refused to deal with her siblings regarding the estate, and ended up estranged from everyone except her own children. I was the only one of her 4 children that defended her to the rest of her family and attempted to mediate. She eventually was able to purchase the family farm (largest source of contention in estate), which she would need to rent out. I stepped up, volunteered 4 months of my time, fronted her $4k to pay for supplies, and did 95% of the work. After the closing inspection, she decided she wanted to move in and rent out her old home. That was the beginning of the end, as I tried to help her put the final details in. Her husband, a buffoon of man, was a constant stressor. He is "dirty old man" creepy (has made inappropriate comments to me several times), doesn't bathe, doesn't work, doesn't have common sense. He would show in the middle of the night and like a leprechaun, would mess up what I had done or destroy something else. He made or altered firearms and would leave them unsecured in the rooms I had completed. I had to bring my then 3 yr old daughter with while I worked there as I didn't have daycare, and set up a room with new carpet and paint as her playroom. I had to constantly tell him to remove the rifle he put in there, and even though I am very familiar with firearms, I couldn't make it safe. He smoked packs of cigarettes a night in that room while he sat with his rifle and night vision goggles to shoot coyote from a third story window. Yes, I know. He would also set off bug bombs without warning while we were in the house. I got so stressed out from getting nowhere with my mother to try to quell the situation; he didn't listen to me and it never got any better. My last straw was when my daughter came to me with watery eyes and a swollen face after being there for 45 min. I packed up and left. My mother never tried to find out what was wrong and acted as though she was oblivious to my past complaints. I last saw her in January of 2015. After that, she refused to pay me back claiming she never approved what I did or purchased. She wouldn't talk to me, but when she did, she would send an email claiming she was too stressed to deal, couldn't afford to pay me back, and played the victim. I learned I was pregnant in Feb and ended up in the ER with a miscarry in April. We had been trying for years, so this was devastating. My mother didn't care. She wouldn't respond to my pain, and refused to return the $2.6k she still owed me so I could pay my medical bills. She set my sister on me then, to tell me what a horrible person I was and how the world was better off that I lost this child. In October I learned I had cancer, and again she refused to communicate with me like a mother should. Instead, she told me of her stress with her job and her family over the will. She did say she prayed for my health. That's the ONLY thing she has ever said about it, but not until after Christmas when I sent back the presents she sent to my daughter. My doing that was the most offensive thing in the world to her and my sister. Neither of them nor my brothers ever bothered to reach out to me after the diagnosis, surgeries, chemo, or radiation. I could be dead for all they know.

I feel so betrayed over the farm situation, but I am without words to describe the abandonment I feel about a woman who apparently couldn't care less that I could have died (or could still) from cancer. I lost my breasts, my hair, and my mother all in one year. I'm not sure what to even do. Do I try to reconcile? Is this a lost cause? Is it worth it? I am beyond sad about losing my mother, but she was never motherly to me. She provided no comfort ever in my times of need, no show of support or affection in my 43 yrs. I will never talk to my sister again. The things she has done to me my entire life ending with the comments she made about my MC....DONE. But I don't have the same certainty toward my mother, but I am not sure she deserves that either.