What are you trying to tell me, legs? (+ a mini rant)

I confess:
I've skipped two long runs in two weeks. It's not that I don't want to exercise- I've still worked out every day I can fit it in- but somehow running has lost it's appeal to me. I do love it, but I'm not a "natural runner," and though I did a 5-mile run two weeks ago and a 3 mile run just a couple days prior, I still get out of breath the first warmup lap around.
I thought at first it was just because I needed to take a rest day, but after 2 days of not working out due to running back and forth between activities, as well as speech sectionals, I went out for a jog on Thursday and still felt off.
My stamina in jumping rope, interval sprinting/HIIT, and other cardio even seems to be improving.
It's just the steady-state runs longer than 2-3 minutes I've been struggling with...
I think I'm just going to do more HIIT session on the treadmill, as well as tabata bodyweight cardio routines + plenty of strength training/moderate lifting and pilates.

Interval training burns more fat/calories anyways, and I've got a goal to shed 0.5- 1 inch from my waist and at least 0.5 inches from my thighs before I head off to China and the land of the negative-in-american-sizes-due-to-vanity-sizing females. Seriously though, girls in East-Asian countries are tiny; a size Medium there is a size XS here.

I'm already bracing myself for all the "Oh my, the American Food does make girls bulky!" I'll be getting from my relatives, and I'm a size 0 at 95 lbs and 5'0. But that's a whole 'nother post for a whole 'nother time. And don't worry about my self-esteem; I've grown up in a society where people simply tell you their opinions of your physical appearance. I know I shouldn't take it as anything personal, and as my mother says, I've got skin so thick 'an armandillo would be jealous.'
She could've been talking about my elbows, but... I will choose to take it as a compliment for vanity's sake.
Ohhh crap I've already ventured into rant category. Ugh I hate to start on something and then leave y'all hanging, but I really don't want to get into my body image issues and expose deeply repressed teenage chinese barbie somewhere inside of me. (Yes I just read that and it made no sense... just go with it.)
I will post something that explains why going to China is a real head trip for anyone without a 23-inch waist later, as well as my training plan for the next week.

To get back to the foot we orignally started on:
Any suggestions about my lack of stamina while running?