So sorry to hear this and am thinking of you. You were a wonderful sister and hope that the good memories soon replace the shock and sadness of your loss. Take care of yourself now.
I don't know how I missed this post earlier. I echo the sentiments above - I know you have been dealing with your brother's illnesses for a long time, mostly alone, and mostly thanklessly. Accept help now; take care of yourself; get support where you can. We're here.