Hello and welcome
Along with the others, I want to reassure you that you haven't been forsaken, Jehovah is still there for you, He is just waiting for you to ask for His help.
I can relate to some of your experiences - I was raised as a Witness, also my mother died when I was young. The deaths of your father and brother are still pretty recent, relatively speaking. Don't feel guilty for grieving over them - grief is a relative experience, we all are affected by it differently. Even Jesus wept over Lazarus, remember, even though he had the power and knowledge of everlasting life! I am glad that you are close to your mother, she needs you at this tough time.
As for raising your son, I'm sure you still know and remember much of what you learnt as a child. The principles laid out in the Bible are the fundamentals for a good life. Jesus said there were 2 primary laws : Love of God, and Love of neighbour. If you show love in your dealings with fellow humans, and still keep Jehovah in your mind and heart, then you are doing what Jesus told us to do.
Stay strong, and stick around. You are also welcome to email me if you wish.