uncontrollable car madness

Like many of my fellow Denverites, I drive my car, a lot. Luckily I have a small sedan which gets ~35mpg. This is great at the gas pump, though when I reached nearly $60 for a fill up, I did have some sticker shock. My gas budget is around $200/mnth, give or take. Seems like a lot; considering it could be double if I drove one of those SUV's that my neighbors have, it's not terrible. Well, this was not intended to be a rant on the price of gas, you can find that anywhere.
I'm decently smart, I can figure things out. Mechanical issues don't scare me. I know nothing about cars. It just looks like a piece of fancy plastic and metal. I know where to put the gas in, the windshield wiper fluid, and where to check the dipstick for engine oil. As frugal as I am, I pay someone to change my oil. Cars have just never been a fascination point for me. I like to look at pretty ones, I admire the fast ones, I drive one. I have been known to play up my 'girl-card' for car stuff.
I drove my car like normal this past weekend in the heat. No issues to speak of.
I drive my car to work on Sunday morning and a few miles away I notice an odd noise (keep in mind, I have no sense of smell, so I have no idea if there is an odor coming from the hood too). I keep driving. About a mile away, there is a loud noise accompanied by steam. Steam is not to be confused with smoke. Smoke is grey-ish and bad, very bad. What I had was steam, white/clearish stuff which is just water getting too hot and condensing to a gas. Not so bad, not good, but again, not so bad.
Realizing that after driving 25min, the car was going to be hot and the last thing I needed was a burn. I strolled inside and began working. An hour later a co-worker asked how I was and I said something briefly about my car.
Enter damsel in distress and the attempt of a knight in shining armor, followed not far behind by a rival knight. Who is brave enough to tempt the steam-throwing dragon which is spewing hot chemicals?
The mouth of the beast was pried open and a hiss and a sputter attacked the valiant knights. They tried to sooth the beast with elixir (radiator fluid). Momentarily pacified, they triumphantly went back to work, strutting the whole way.
When it came my time to get her going again, she was furious. Less than five minutes into it, the steam was raging and the engine was roaring. I tried pulling heat from her to alleviate strain to little avail. By the time we got home, we were both so exhausted it was all I could do to reign her in.
What does this all mean?
I drove home when it was 100F outside and I had my heater turned on full blast. Talk about misery. I didn't even have to pay for that sauna treatment, pore-cleansing experience.
Basically, after investigation and a few minor burns (the same ones I had earlier wanted to avoid), I found out that my radiator had a 2" crack in it. This knowledge came to me at 5:30 PM on a Sunday. Guess what isn't open? That's right, repair shops. I had to be at work at 5 AM--not going to happen.
With much investigation and some stress and feeling so little, I managed to find a repair shop close enough not to need a tow that said they could get the work done today. I'm tempted to believe them, though they have yet to prove themselves one way or the other.
Currently I have not a clue as to why my radiator developed a crack, a sizable one at that. Car only has 75k miles on it. Sometimes, things like this just happen.
And my third knight is on his way to take me around my castle so I don't disappoint my village. [he's helping me run invaluable errands].
Chivalry is not dead, though my car might be.