My ex wife has been in and out of the hosp she I just found out that she filled up the bath tub and was thinking of drowning the kids and she has tried to commit suicide twice can I get full custody so she can't see the kids.

Not unless you file to get it. And I would do that ASAP.

You might not get sole physical custody, but you should be able to restrict her to supervised visits.

What is the custodial arrangement now?