Mom on palliative care, family at war!

Hi all, 

My mom is on palliative care. I love her so much. I live a distance away so I spoke to her most days if not daily through video chat. I have helped with getting things sorted for her. There are several siblings but we don't get on for various reasons. I have a step-dad who has left me to sort out the palliative care and other things. I was also the one who had to speak to the doctors because he couldn't. Mom called me first with the diagnosis, while crying. It broke me, I cried and cried. I lost my dad at a young age. I'm close to my mom. Mom is in hospital now and not expected to leave hospital. I have visited her  and spent many hours at her bedside. Last night I received a really nasty message from a sibling, it told me that I was no longer welcome at the hospital to visit and to cut contact. It said they were sparing my feelings but my mother never wanted me there. It hurt so much! Even though I know it's not true, it broke me!  It went on to say they would deal with the funeral and I would receive details as and when but to not get in touch at all.

This morning, I received a phone call from another siblings phone, when I answered it was my mother. She told him she wanted to speak to me. He used his phone so she could call me. I asked if she was okay and she asked how I was. I told her I love her so much but have received a nasty message from telling me not to visit and who from. She was angry, she said "How dare he, he has no right, of course I want to see you, he's an A***hole, she doesn't usually swear. I said to her, you know I love you don't you mom, She said "Yes of course I do, and I love you too!" At which point, sibling who helped her call me, asked her "Do want to see (My name)" Her response was "Of course I do!" I don't know what to do. If she is now on morphine, will she still be lucid? I want to go and see her if she wants me to, but they put her on morphine continuously now to control the pain, will she be sedated to the point she won't know we are there or will she know if I go and see her?

Can my sibling tell the nurses not to let me in?

I'm feeling so upset, I'm struggling to cope and it's actually making me ill.