Marylin, you seem to have a good, level head. You realize that you deserve help and that you are lucky to receive it. You are a strong person who should not feel guilt for circumstances that weren't of your choosing and are beyond your control. You are brave, too, because you're still fighting. You still want to help yourself.
Being sad about your loss of certain abilities is natural. You are mourning the passing of aspects of yourself that you've had your whole life. Allow yourself to grieve and don't feel guilty for that, either.