Please Help Me ID This Episode :(

I am going rather nuts about this and have for years. I'm not even *100%* certain - but 99% - that it was an "Outer Limits" episode.

I don't remember much of it, but I'll do my best.

Space ship, alien presence that causes hallucinations. People are dying, etc. In one of the creepiest endings ever, IMO, one of the characters, female, who has been fighting against the whatever that's taking over people's brains has successfully beaten the enemy and navigated the ship back to Earth.

In the last shot, she's having a conversation with one of her shipmates, and looking out into space at the approaching earth, she says "I can see it."

At that point, she repeats the line a couple of times, maybe, and we crossfade to find that our heroine has become one of the victims of the alien intelligence, and her success is an hallucination. The last lines of the episode are her voice repeating: "I can see it...I can see it..."

No amount of badly-remembered synopsis is going to put over how incredibly mind-wracking this episode was. I seriously have strange dreams - wouldn't say nightmares, but strange dreams - to this day in which I hear that voice: "I can see it...I can see it..."

I saw the episode once - maybe only part of it - and it must have been 15 to 20 years ago, but I've never forgotten it. I've now read through all of the episode descriptions for this series, and while a few suggest possibilities of being "the one" (e.g. "Manifest Destiny" in S6, "Relativity Theory" or "The Origin of Species" in S4, "Tempests" or "Bodies of Evidence" in S3..."Worlds Apart," "The Light Brigade," "The Second Soul..." none of them are descriptive enough to make certain whether I've got the right episode, and I don't have the time or resources to watch seven seasons of this show to find out.

Can you help?