Love yourself first putterfit. It sounds like life has knocked you to the ground more than once but you're still here trying...that's what survivors do even on their worst days. I long ago stopped expecting life to be "fair" what ever that means and by who's definition!
You mentioned other children..that it was your youngest son that completed suicide. Those living children are reason enough to go on...you don't want to leave them that awful legacy..and you can see what it is doing to you. Guilt, anger, ....I'm so glad you are talking about it.
Cancer (MS) can take away all my physical abilities. It cannot touch my mind, it cannot touch my heart and it cannot touch my soul. And those three things are going to carry on forever. Jimmy V " Your signature line.