I Am Very Worried about Myself and My Best Friend

Today at about 5:30 pm at the store, I reached up to touch something and my whole right arm went completely numb. At that moment I thought of a gazillion things it could be, from stroke to a pinched nerve with a heart attack somewhere in the middle of it all.
I still don't know what it is but my arm doesn't feel right. It doesn't hurt but it doesn't feel right. There is a minor stinging sensation going on here and there in the arm now.

My best friend Rachel, has given me permission to read her Diary from time to time. What I read today was upsetting as well as scary. Upsetting because she indicated she was so depressed that she gave very strong thought to suicide. I honestly thought that chatting with her as I do, she would have shared those feelings with me and I could have talked to her and helped her deal with those feelings. I am glad she decided to go to a doctor and get checked for whatever, but I am somewhat hurt that I didn't even know or have an inkling.
I think of her as a member of my family, as a daughter and I would do whatever it takes to help her. Damn it, Damn it, Damn it - why didn't she tell me. It hurts because I feel I wasn't trusted enough to tell.
The only thing even close to saying anything was, she did say she was feeling down in the dumps but believed it was the gloomy weather they were having. I guess I am going to have to start reading between the lines, I never thought I needed to do that with her, as she was always so open with me. I know she told me stuff she didn't even tell her husband. I wonder if she shared her feelings with Jon, I would like to think she did, but now, I wonder.

Back to me, if this condition persists tonight, I think I should go to the hospital to be checked. I do think it's a pinched nerve though - not life threatening or a heart attack.