Does COVID leads to ARDS? Once clots finish, could they become again?

Hi,

I got Covid. It was its 12th day and suddenly my oxygen started to reduce and my breathing was very short. Suddenly it reaches to 44% and I admitted to hospital and doctors straight forward said SORRY! There is no cure! My luck that a senior doctor came and he prescribed Actemra (Tocilizumab) Injection. In 4 days, they injected 4 injections to me and I started to get better. My oxygen reached 88 in 10 days. My doctor gave me Rivaroxaban for 30 days and my D dimers got better.

Doctor said you had ARDS.

I’ve some questions if you people don’t mind to give me some answers and help me.

1- Did ARDS happen to me due to COVID?
2- Did clots produce due to COVID or ARDS?
3- Once clots finishes, can they become again?
4- Once ARDS finishes, can it happen again in life without any reason and is it treatable?
5- For what they used Actemra Injection for me?

I would be grateful if someone gives me answer and clear my concept.

Thanks,