toilet training my 5 month old

by ang
(scotland)

i have a 5 month jack. we are having no success with toilet training.

he pees and poos all over the house. sometimes hiding other times he squats in front of me.
he can hold it when in his cage so ive had to cage him overnight.
he's quite happy and cries to get out if he needs during the night.
i go home every day at lunch time to let him out, but quite often he holds it in, sometimes he does go.
i've taken him out for 2hrs at a time, he refuses to go outside but as soon as we are home he pees.
to add to our problems im pregnant and feeling rather stressed by his behaviour. my partner is on the verge of rehoming him. he's a great dog in ever other way.
HELP!