Aww, ganyan din si baby ko dati, super stressful! Usually it's either may sakit ang nipple mo kaya masakit para sa kanya, or frustrated siya kasi hindi agad ang flow ng milk, or kahit naman di sya komportable sa position at latch pa lang talaga ang issue. I'd really suggest checking with your OB or a lactation consultant soon kasi kung pain yan ang root, kailangan ayusin ngayon pa lang para hindi ito maging bigger problem later. In the meantime, make sure baby's mouth is covering the whole areola, not just the nipple, at try different positions to find kung ano ang comfy sa kanya.