Yes, you definitely have to dust yourself off and get back on. Just think - the average rider crashes every 4000+ miles, so you should have many more miles of beautiful riding before you have to kiss the dirt again

I actually had something similar happen the first time I went riding. It was just a half-mile loop, but at the very end it had this killer hill (well, it looked killer to me at the time). I didn't know anything about gearing at that point, so I just rode up it in whatever gear I was in. Made it to the top but barely. My house was only a block away. Got the bike up into the yard, went to go up the stairs, and DP had to catch me from falling. My legs just totally gave out. It was less than graceful

Don't worry. After just a few weeks (and figuring out the gears) I was doing 2 miles without any problem, and I just did an 8 miler yesterday without killing myself. Just go at your own pace, ride as much as you can, and everything will get better.