Losing ground

I'm caught in this cycle rotating between anger and sadness, passing frustration and hopelessness in the process. It reminds me I will never get used to this. Even the slightest improvement in my health makes me realise the extent of the bad shape I was in. And it will never stop feeling so very wrong and unfair. I can't prepare myself for this. I can't shield myself from these feelings. They swipe me off my feet and make me about as useless as I was before. 
I need to find my ground back somehow. Find things I can believe in.
But there is a voice in the back of my head that asks me- even if you find them back this time, will this also happen the next time? And the time after that? And if it goes on like this for another decade? Won't it slowly break down my defences, suck out my energy?
I'm overwhelmed. I don't have the strength or resources to somehow handle this. I feel like a puppet of my fate. Thrown around by my emotions. Covered by this weight yet stripped of everything else. Simultaneously empty and overloaded. And there is no fabricator who is responsible. Nor was there ever a manual. It are the strings that make me move. Everything else to me feels like permanent rigor mortis, frozen after the discovery of lifelessness. Dead and rigid like carved wood. Living a life that doesn't seem mine.
That I don't really want to be mine.