Nice start, and a compelling story. Can I assume this is for a college course? To submit to a magazine? Of course who your "audience" is makes a big difference. Since you indicate it's supposed to be a descriptive essay, I'll go with a school assignment. I'm not going to point out your typos, etc., but here's my semi-professional opinion (I'm a writer).

I'd like to see a little more description about the symptoms you experienced. Did they all start the same day? Talk about how they might have come upon you, what you thought they might be. When you called your mom, was it to say Merry Christmas or for advice?

I'd also like to know how you felt when the doc came in and announced you'd had all these mini-strokes, telling you you weren't going to leave the hospital. Did you call your mom? friends? Was anyone with you at the hospital? At 24 any of the three choices would've been terrifying.

A revision describing the upheaval, and your fears, maybe mention things you had thought you would do later in life suddenly looking like they wouldn't happen, etc.

I wrote an essay about my testing and dx experience. I think the reaction I wanted to get from readers was "Geez, is that how it felt? That really sucks." This would be especially true for your story since this pretty much destroyed your Christmas that year. Tell us how much this ruined Christmas for you, or maybe how it ended up salvaged in the end somehow.