Be careful on watering. Im very doubtful your problem is linked to underwatering but yet the exact opposite. Underwater you can USUALLY tell because half the plant will look perfect and the other half will be drooping and almost look wilting. Overwatering USUALLY looks as yours do and will just have an over all droop to the plant. With you being new to growing as we all have done you just wanna take care of your babies and prolly are watering them to often or too much at a time. EVERYTIME i have underwatered a plant and then gave it a good watering within hours the leaves have perked almost straight, telling me obviously thats what she wanted. If your overwatering you wont see a change other then maybe more droop. Cannabis plants grow in warm conditions where rain isnt every other day or even every 3rd day. They can go a good week without water. If your soil is wet and your leaves still look like that after 5 hours id say..... your overwatering. Let your soil dry out and cut back the water. IMHO