do you work an afternoon shift?
like 3 to 11? if not,
i was thinking if all you need was for you stbx to have the kids from after school until you get off work at 530 you could get shared parenting. i was under the impression that a few hours after school might not really make that much of a difference....
maybe split the week sat- tuesday with you tuesday to saturday with him.
your weekdays you can have a sitter or he can take them after school for a few hours.

how is just a few hours having you loose so much time?
how are you not getting a the very least 40%?

this is just heartbreaking to me.