How to potty train my 4 mos.old boxer?

My girl Brittney, has been with me since4 days old, the mother rejected herand i bottle fed. I always take her ond leave her out for most of the day and as soon as she comes in she pees and poos any- where she wants, then i rub her nose in it and put her rite back outside. She has also been into the bathroom garbage eatting my menstral dirty pads and tampons (gross)Whats up with this pup, shes driving me nuttttts!!!!!!