not coping, cant think straight any advice please

Sorry to hear this. My sister has just been told her cancer is terminal and she only has a few months to live. I am devastated. Our mum died not long ago and I can't get my head around that I will lose my sister within a year. I am trying to see her but she is shutting me out. I can't imagine what she is going through, and feel so guilty that it appears I am making this about me when it is the last thing I want. I just want to spend precious time with her. I don't live close by, so I can't just pop round. I can't focus on my job, sleep or feel like eating. I am so distraught for her, her child, her husband and our dad. She is refusing to tell her child the therapy has not worked. I don't know how to handle all this and think I am very selfish moaning about myself considering what my sister is facing.

Oh gosh I really feel for you can't imagine how your feeling, I'm same feel guilty for having feelings but can't help it, I also live quite a few miles away from my mam so it's hard to organise transport for hospital visits plus covid restricted hours at the moment so don't feel like I'm doing enough, but also need to be in work and be a mam all at the same time it, stil can't believe this is all happening, here if you want to chat anytime, 

My dad has been diagnosed with lung cancer. I can understand how's it feels to be shut out,as he didn't tell me,my brother did. He has been so distant the last couple of years with me and my brother,missing spending time with my 5 year old son and my nephews 4 and 5. I have messaged him letting him know I'm here for him and I love him. My brother is focusing on other things so is very shut off from his emotions in this. I have a loving husband but I still feel so alone in this. Don't feel selfish for feeling like this,when it is someone you love it's devastating for all involved. I found out yesterday and have work on Wednesday where I work in retail. The thought of being around all those people while I'm trying to deal with this is overwhelming and scary,I'm so worried about bursting into tears 

Thank you for replies, advice etc it's been so helpful being on this group unfortunately I haven't been in here for a few months, 

Sadly my mother was diagnosed with AML 4 weeks later she passed away so now having to change from. Dealing with the shock of her being diagnosed to now going through berevament x