Since the 3k is ran at a speed lower than vV02max, you defenitely need some anaerobic stimulus to make it worth it.
Also you don't have a stress facture yet on both shin so everething is going perfectly well. You might consider adding some 1000s during the long run ans 300s after recovery runs.
No pain no gain so the more painful is your body, the better it is. Actually having several stress fracture a year shows that all those who tell you to take it easier are wrong. The bigger is the stress, the bigger is the adaptation. GO ON.
Also don't forget to add some Salazar's workouts like Mo Farah. Yeah if you wanna run as fast as him, you have to do the same workouts, that's the way!
Be careful, you should never feel good or conformable any day. That is for lazy hobby jogger. not you!! As soon as you don't feel exhausted, add a workout. As soon as you don't feel shin pain, go on pavement for a long run.