You Jump In The Deep End Too Quick. Your Story Structure is Off.
I'm pretty sure your story is "rushed" because you did not spend enough time in the setup. At 3000 words, I don't think that is possible. You say your story begins:
MC heads off to work to confront her boss about something; MC collapses and is taken to the hospital,
You have tried to begin the story with the inciting incident; having to confront her boss about something (which I presume leads to her collapse: If the confrontation does NOT lead to the collapse, that is a story flaw and broken linkage; because she could have just gone to work normally and collapsed, and the whole "confrontation" thing was a red herring).
Good stories do not begin that way, not even short stories. They begin in the MC's normal world, so the reader gets to know them, BEFORE the inciting incident forces them OUT of their normal world to deal with a problem.
This is part of the Three Act Structure (3AS). Note this was not invented, it was derived from the analysis of many thousands of popular stories, the analysis discovered that popular stories tend to follow this template fairly closely. Emulating it will help. The "Hero's Journey" was also derived from legends and myths that have stood the test of popularity through centuries, but I consider it a specialized (and more detailed) subset of the 3AS, not an alternative. There are others like that, Shakespeare's Five Act Structure is an example.
I prefer to divide these into [Act I, Act IIa, Act IIb, Act III], they are all approximately equal in length, 25% of the total story -- But give or take 10%, depending on your needs; i.e. none of these four pieces should be less than 15% of the total, or more than 35% of the total. A story with a large cast of characters might demand a longer Act I to naturally introduce them all. (Although a story like Ocean's 11 spends a long time introducing Clooney and Pitt, then introduces the other eleven main characters (including the villain and love interest) in fairly short vignettes).
For a given word count (and it sounds like you have one in mind), the "inciting incident" (also known as the "call to action") occurs in the middle of Act I. That is at the 12.5% mark in the story. The MC should leave her "normal world" at the end of Act I (25% mark). To me, that is with your car crash.
Which means nothing very important happens in that first 12.5%, the reader is being introduced to the MC (and perhaps supporting characters), the world, her normal life, and getting to know her.
In order for readers to sympathize with her, you need to give her some problem, something she cares about. This can be a "throwaway" problem, meaning it doesn't have to influence the plot (better if you can think of a problem that does), but it exists to show us something about the MC's character and abilities. For example, she wakes up late for work because there was a power failure while she slept, and she also has to get ready for work by the light of her phone without electricity.
Or her car won't start, and she has to call a cab. Or any number of other minor problems we all have with day to day life. In the first 12.5%, you still need conflicts to pull the reader along to the inciting incident, but these early conflicts are of a special type, they are only there to shine light on your MC from different angles, for the reader. To make them see her true self and like her, so they care about her later when she is in danger, collapses and gets in a car crash.
Because of this different flavor, these early conflicts can be throwaways, or humorous, and are seldom life threatening or dire. For example, accidentally burning your breakfast because you are distracted by dramatic news on your phone (news that might be indirectly connected to your plot).
Again, the 3AS is not some law passed that for some reason all readers from 2 to 102 have agreed to follow, by refusing to like books that do not follow it.
The 3AS is science, the result of distilling stories readers already love and figuring out the pacing those stories have in common. That is the 3AS, and indeed, if you follow it, your pacing will work out, and when you don't, people think your story needs work. They may not be educated in literary science, but what they feel naturally a story needs is missing. That is what your friend is telling you with "it's rushed", that you did not spend enough time making them care about your character before you dropped her in the river. That they are not sure yet if they even like her, or should root for her, and they have a need to like her and you have a responsibility to show them she is likable. She's feeding a stray cat, she helps out her neighbor, something that makes her human. Use your imagination. Compress or cut down some other part of the story, you truly must begin your story in her Normal World and let us find an MC we like there, before your inciting incident. If Act I is only 15% of the story (IMO the bare minimum), then 7.5% of the story must be her Normal World.