Where does taking inspiration end and stealing an idea begin?

My current fixation is SIGNALIS. It’s a game where you play as an android - LSTR-512 - looking for a member of her crew in a facility, which’s whole staff got infected and turned into monsters. By developers the whole gaming experience was described as ‘’having a dream about dreaming’’. I love this game with my whole hearth, but this love makes me subconsciously borrow a lot of ideas from it and I’m tired of it.

I started creating my own little universe in like 2020. For a longest time it had no real substance, just bunch of OCs thrown together in an unbuilt world. Recently I finally started writing down my ideas, but the more I write the more I feel like the ideas I have are not mine. Even tho I know I’m not ripping anyone off I can’t stop but see similarities between my little imaginary world and SIGNALIS.

My main character? Android. Not even because I like this concept but wanted to base her on an animal without making her a furry. But androids in SIGNALIS are also loosely based on animals!

World? Based on Poland during communism - in SIGNALIS it’s based on Germany during communism.

Main plot device? Dreams. I had this idea I wanted to make my stories around dreams since forever, before I played this game and even before it was made. But I can’s stop seeing this similarities.

And I know, few similar aspect doesn’t mean the whole idea got ripped off. I don’t even plan on publishing it anywhere after I finish it, it’s just supposed to a thing a think about before going to sleep so my thoughts aren’t cluttered with negativity.

How do I get out of this goddamn cykle?! (Hehe, it's a SIGNALIS referen- FUCK!)