Growing indoor can definitely be overwhelming the first time if you arent 110% prepared (who ever was on their first try?).

It would be smart to invest in a PH pen and a ph adjustment kit meant for gardening. Also you will need circulation fans and an exhaust fan. Dont forget about nutrients.

Do you have any pictures?

Your temps and humidity are fine. Without an exhaust fan how do you provide them with fresh air? Also it would help to know exactly what kind of soil you used.

Your problem is most likely a combination of things. Not providing them with "new" air, crappy soil, and no food.

pics pics pics!!

By the way white widow is not an auto flowering strain.