Im sorry youre feeling this pain. It is hell! I hope you find comfort in the near future. Keep fighting for yourself.
I don't think it ever truly goes away. It is not natural for a mother to live longer than her child. We are suppose to be the ones leaving them behind. And your right, it is like a rollercoaster, you are going along just fine and a memory hits you and you are blubbering mess. Just hang in there.