Diary - I just read some comments from people who had caught Covid-19

[Maybo]

This is an entry from my diary. Please check it and correct any mistakes.

I just read some comments from people who had caught Covid-19. Some of them said they felt dizzy, but when they lay down on bed, they were fine. Me too! More seriously, I had felt dizzy for a month, and I almost requested to do a brain CT scan. Those people also had insomnia. Me too! However, I didn’t do an RAT to check if I got infected because I didn’t have other symptoms such as fever or sore throat. Now I think I might have caught Covid-19.

 

[emsr2d2]

I just read some comments from people who had had caught Covid-19. Some of them said they felt dizzy no comma here but, when they lay down on the bed, they were fine. Me too! More seriously, I had felt dizzy for a month, and I almost requested to do a brain CT scan on my brain. Those people also had insomnia. Me too! However, I didn’t do an RAT to check if I got was infected because I didn’t have any other symptoms such as a fever or a sore throat. Now I think I might have caught had Covid-19.

See above.

 

[Maybo]

When should I use “had caught” or “had had”?

 

[emsr2d2]

When an illness is over, we usually just use a form of "have".
Last month, I had flu.
In 2017, I had mumps.

We tend to use a form "catch" when something is ongoing or current.
I think I've caught a cold.
Don't come near me. I might catch what you've got.

However, if the important part of the sentence is about the illness's transmission, you can use a form of "catch" in other tenses.
My uncle caught Covid in hospital.
Catching Covid won't be the worst thing that happens to you this decade.

In your opening sentence, the fact that those people presumably caught Covid from someone else is irrelevant. The important thing, for you, is that they have experience of being infected with the virus. Therefore, it suffices to say that those people had had Covid.