Overwhelmed

I am a 47 year old single female who has always been extremely close to her parents.  I never had much confidence in myself and due to my weight feel unlovable.  I have done everything with my parents.  I never married, never had kids and now find that my dad has Myasthenia Gravis and just had surgery for kidney cancer.  He has been like a rag doll-stuck to his chair.  The very active handyman of a dad that took care of the house and took care of us is now this fragile, weak old man.  My mother has been experiencing extreme sciatic nerve pain and has been told she has major back issues.  I go to what was once my solitude with my loving parents to find my mother crying in pain.  They have appointments practically every day and my once happy mother is now overwhelmed with trying to keep my dad's medications straight and taking care of him when he always took care of her.  I feel as though they are slipping away and yet they were always my life.  It is so hard to see them struggling and I feel lost.  I almost feel as though I am right there with them and my life is almost over as well.  I am so greatful for this website.  It has been nice to be able to give my parents some answers and feel as though there is something I can do to help in a very hopeless situation.