Of course girls are right! I thought that maybe it will comfort you if he is actually making a lot of poos, but it's definitely not an argument for any panic or problem.
I cannot help with info about getting period, but I guess that one of the most problematic thing hre is that you must not panic as THIS WILL affect your supply. If you are sure in your mind that there is no milk for your child, you will make that happen finally & your LO will feel your mood. I was in this loop couple of times until someone tolf me "hey, stop making panic!".
Try to comfort yourself before feeding. When he is on your breast - talk to him slowly, comfort him with your voice. Even when he is fighting with you, make some pause and try again. Maybe try different feeding position. And think positively and talk to your child "hey little one, there is plenty milk for you but you cannot be so impatient".
Remember that even if you milk supply is/was low, it takes only about 2 days to increase it. And even if you are not successful that's also fine - there are milion of solutions how to feed you baby and there will be nothing wrong if you will decide on one.
I am sure everything will be all right. Keeping my fingers crossed!