Отлично! Спасибо!

Grumbler, although your translation is quite accurate word for word, I wonder if you understand the meaning of this statement.

(то, что я рассказал) было на самом деле, но лучше бы если все это я лишь придумал

This is another way of saying “I hate to say this” when you relay bad news

“I’m sorry to have to tell you this”

“I know this is difficult to hear”

"So, what does space smell like? Well, gunpowder. I wish I was making this stuff up but I’m not. According to astronaut, Peggy Whitson, space has a bitter and smokey/burnt smell to it."
I see neither anything bad nor an apology.

"I WISH I WAS MAKING THIS STUFF UP BUT NO THIS IS MY LIFE"

"Luckily we had asked for extra linens... But the backup had hair on it and a child's sock fell out of it... Dirty w/more hair on it! I wish I was making this stuff up! "

In all those cases, the speaker is saying “I know this sounds horrible“

I didn’t mean SORRY in the sense of an apology, but rather in regretting to have to tell someone something.

However, the examples are about the speaker's experience. IMO, it's rather "hard to believe" than "difficult to hear".
I can offer "В это трудно поверить, но я это не выдумываю/выдумал" - more idiomatic, but more remote from the original.

Naturally, you can translate it any way you see fit - I can only speak for the English. All I can say is that “в это трудно поверить” doesn’t quite say it. If you examine it, it means “I wish for your sake that I had made this up, but the bitter reality is...” It’s not about the veracity of the statement, but the unpleasant nature of it. It’s a figurative “apology” for something that may come as a disappointment to the listener based on their expectations or beliefs: “You say you want to learn Russian? Well brace yourself of a lot of study, memorization and frustration, because even if you study assiduously every day, it’ll be a good four to five years before you’re able to take part in even the simplest conversation. I wish I was making this up, but the fact is that Russian is so extremely grammatical that even the numbers are declined.”

= I know you’re eager to start using the language, and I’m sorry to be the bearer of bad news, but you won’t be speaking it any time soon.

Да, я согласен, что это о собственом негативном опыте с целью предупредить собеседника, но, ничего другого придумать не могу. Думаю, в контексте мой вариант будет звучать нормально и понятно.

👍🏼