Crashed on a faraway planet with retrograde amnesia, a young, ingenious but highly schizophrenic astronaut strives to rebuild her spacecraft while endeavoring to outwit a manipulative, shape-shifting alien whose sole impetus is to repopulate by abusing her as a host.

Thank you all for the feedback! I understand how it’s challenging to suspend disbelief on the schizophrenia aspect. It doesn’t make sense. My apologies for that — I am removing that detail, as it wasn’t as relevant to the story after I reanalyzed it. I also want to clarify that retrograde amnesia is only amnesia that removes memories, not skills. For example, this astronaut may not remember what car she once had on Earth, but she’ll still remember how to drive it. The same concept applies here to the spacecraft, which is why I believe it’s important to specify that the amnesia is retrograde, and that it is progressive (worsens over time). To keep it at plain language, I think I can replace amnesia with memory loss, but specify that it is progressive, and achieve the same, albeit more clear result. With all your extremely helpful feedback in mind (which I deeply thank you for), here is my revision:

Crashed on a faraway planet with progressive memory loss, a young astronaut must rebuild her spacecraft before a shape-shifting alien makes her the host to repopulate its world.

I’ll post this, marked with (2nd revision) on another post. Thank you again. I look forward to your feedback.