I second what Leed said about medication and what Shez said regarding your kids and your safety.

Certain mental disorders can be aggravated by antidepressants. They can be helpful but are also not drugs to be taken lightly. And yes, your kids do not need to be around a mother like this. I almost think a temporary separation -- until these things are worked out -- may be a good step. Your children should understand at least your choice to keep them from her for awhile.