I'm still curious how you're structuring your training. Are you doing periodized training? What's your total volume?
The first time I broke 15, I was in a periodized program, averaging 75-80 mpw, and it was relatively early in my season. To that point, I had done mostly threshold/mile pace and was starting to work in 5k pace stuff. The 3 weeks prior, my workouts went like this:
2 weeks out
Session 1 - 2x200, 2x800, 4x400, 2x200 in roughly 63-65s quarter pace
Session 2 - 4 mile tempo in 20:50
Session 3 - 2x3200 (5:15 pace), 1600 (4:45) 2x400 (64s)
1 week out
Session 1 - 2x1600, 4x800 avg 4:45 pace
Session 2 - Road 5k in 15:20 (win)
Week of
Session 1 - 4x200, 2x800, 4x400, 2x200 (64 quarter pace avg)
Race - 14:56 5000m
I think you're going to kill yourself with 2k repeats at 5k pace. 1000s-1500s is a much better target. And they need to be well supported with good threshold and mile pace development.