Is this what they call "Junk Miles?"

I did a little over 4.5 miles today, and had a really rough go of it.  For some reason my "comfortable" pace felt SO slow to me, like I was shuffling along rather than really running.  So I'd get annoyed with that pace and try to push myself "just a little" faster, and end up feeling horrible and getting this weird feeling like someone was standing on top of my stomach.  So frustrating!  I made it over halfway through with alternating between these two extremes before I finally started walking little bits here and there.  I couldn't make up my  mind whether I was trying to primarily complete the distance (and not worry about the time), or trying to hit a certain pace (but maybe not get the entire distance in).  I ended up arguing with myself for most of the run, throwing in some walking, and finally settling on finishing the distance I set out to complete.  From start to finish, I complete 4.58 miles in ~70 minutes.  That time includes stops at at least 6 crosswalks - so I don't know how much difference that really makes.  My pace was close to 16min/mile, which was discouraging.  The Disney course requires that you maintain a 16m/m pace in order to be allowed to finish the race.  Today's run has me wrestling with doubts and frustration.  I'm hoping that's a normal part of being in your taper before your first half marathon.

I'd love to hear any advice from experienced runners about how I can make sure I'm in top shape for my race.  Is there anything I should avoid? I know I should steer away from caffeinated beverages and try to focus on healthy, whole foods.  I read that you're not supposed to strength train during your taper - is that true?  I'm absolutely ITCHING to get back to my weights routine, and feeling like a major couch potato with only 3 workouts a week. 

Someone tell me everything is going to work out.

I will console myself with visions of the tutu I shall wear while running.  Even if I end up shuffling through the whole race, at least I'll be shuffling in a tutu.

The only question that remains is, do I go for a red one to match my shirt? Or do I go cotton-candy style like this beauty?  Choices, choices.