Dear friend, I was over 40 before I began to really come to grips with a lifetime of depression (and I should add panic attacks and a variety of phobias -- spiders, bees, wasps, sometimes even closed doors...). Yoga, relaxation techniques, and self-knowledge are all ways of alleviating the problems. Psychiatry also helps to pinpoint problems and to initiate behavioral patterns to help you cope. But none of them is a cure. That I found only in meditation. But to this day I do a few yoga exercises each day to limber up and stretch and relax my muscles (althought at my age, I am thinking of taking up Tai-Chi as a gentler way to do the same thing), and I still initiate relaxation techniques when I am overtired and can't get into a quiet place to meditate for 15 or 20 minutes. Self-knowledge and coping techniques and information help enormously to help you to understand how you got from A to B and how to school your behavior so you can get through the days, but both involve stress -- the stress of remembering things you wish you didn't have to face -- reliving them in some forms of psychiatry -- and the stress of "trying" to mold yourself into a coping structure.
The only thing I have ever found that helped panic attacks and phobias is meditation, and it is a long-term cure, not a short-term effort. Think of how old you are. Add to that the learned behavior from your mother (who went through the same process with her mother and perhaps father, etc.). Figure how many years it took to create your depressive reactions to things, and then figure that as many years as that will be needed to completely clear you of all the learned symptoms. Factor in the genetic tendency, and you have a mountain to climb. It is a very, very slow process to a cure. You can manage to cope, to paper over things until you are ready to deal with them, to manage your life within the norms in a much shorter time with good therapeutic help and coping strategies.
So you have to attack the whole thing from several angles.
I would not get into the habit of calling depression or panic attacks "mental illness." This emphasis on illness (mental or otherwise) is a negative concept and creates a sense of unworthiness, abnormality, and certain failure. Think rather that you have a mountain to climb that many have climbed before you, and that you will succeed no matter how many times you slip back down into the well. A well which, by the way, will get more and more shallow as you repeat the process. Every small step that you advance up the mountain is a victory of your inner strength and resillience. Every time you slip, you should tell yourself that you made the last bit before, and this time you will set yourself the goal of getting a little further up. Every time you slip, you will slip less far. Don't despair, and don't let depressive episodes break you. Look on them as learning experiences. Examine how you feel when you have them. Determine the things that brought them on, and try to see what your contribution was to the depression. Many times depressives set themselves up to slip. They marry someone or become close friends with someone who will verbally abuse them with words like "crazy" "sick" "out of control." These words may even be objectively true at any given time, but you disgard them because they are negative, and your goal requires positivity.
I think your analysis of your mother's feelings is really very good. You are very wise -- seeing the game is halfway to invalidating its influence on your progress.
You cannot live your mother's life. My own progress was too slow to help my mother, but perhaps I could not have made any difference anyway. When you try and try and you simply can't help someone you love, it is perhaps one of the saddest things humans must cope with. But you are not guilty. You are doing the best you can.
Your last sentence is the only answer for the "new" generation who were able to avail themselves of all the many advances in psychology and the many social services established to be helpful. Accept what you must, and go from there.
I think you are just wonderful. I truly hope that your efforts will bring about more life-satisfaction for both of you.
Love and peace,