Aww, that sounds uncomfortable talaga, lalo na kung masakit at nakikiti! A few of us mums have dealt with this, usually it's chafing from sweat or friction, especially pag tag-init, or sometimes yeast infection if it's really itchy and may discharge. Best to check with your doctor para malaman kung ano exactly ang cause, kasi may iba't ibang treatment depending, pero in the meantime, keep the area dry, wear breathable shorts, and avoid tight clothes to let it breathe. Hope it clears up soon, mama!