[Fulcanelli]

-First impression decides all, make a very good one. Don't start out (semi-)negative. In certain branches (medics, philosophy, religion, social work) a rather whimsical approach comes off very negative. You're not trying a new flavor of chips you found in the shop yesterday, you were born/destined to. Show your future employer that you are a reliable force, and that you're here to stay.

-Instead, I'd start out with your newborn child. Call it a joyful event, not an unplanned one. Don't mix concepts like "life" and "unplanned/nonchalance/accident" in the medical field. Work your way towards themes like "how this event confirmed your awareness", "fragility of life", and being passionate about it. Make the reader relate to you, after all, he/she started out from ideology/passion, and probably has kids too.

-Stay on topic, e.g. don't jump from "childbirth" to "talking to physicians" to "knowing what it takes to be a physician" back to "childbirth". It'll cut away plenty of the repetitiveness in your letter. Keep it simple, keep it clean. Avoid heavy structures, after all, you'll probably be 1 of a few hundred(!) applicants. Make it easy on the reader, and stand out of the crowd/show your intelligence through clarity.

-Selling cars doesn't show the reader your sense of humor; it shows you take up your responsibility like a real mature man when you need to. Even though it's not your dream job at all. That's not "funny" (cut the sarcasm), it's a huge asset/something to be proud of. And it's bloody serious. Now make it sound like that please.

-And no, you didn't sell cars because your wife told you to, that's a pack of lies from now on. So is "After several months spending endless hours away from my family selling cars, I started to broaden my search for something that would let me start spending my time with them." and "This was one of the first periods of my life that I was unsure of what career path I wanted to choose." Cut it out, because:...

-You were born in a family of physicians, you know the drill, and you love it: it's your destiny too. You didn't "shadow doctors", you got "working experience", as an assistant, nurse or whatever. You didn't spend "many hours", you "jumped at every opportunity you got". What's even more, you have proven to be able to handle the pressure of an emergency room. Either don't mention you only worked there for a short time, or specify why you didn't last long (if the reason you quit is something positive, like your daughter/exams/it was a student job).

-That's why you followed a course at Cardinal Health too, and you love it there. You know people, people know you, and they know you talked to them. Don't stress the obvious, mention it casually to make the following point: I know I'll fit in the structure.

-The fact that you're aggressively pursuing is self-evident. As your life story shows, you always were. Change it to "looking forward to meet you in person/personal interview to discuss matters in-depth". Don't end in a semi-negative note either, in the medical field you need to be available at all times, work longer hours etc. Of course your family is your number 1 priority, but I'd forget to mention it (as it's again, self-evident).