My sister was/is a marijuana addict (She was a heavy user before, but now she tells people that she isn't. However, she is also a compulsive liar.) She showed similar patterns to your wife - out at odd times(she often drops the kids off at my parents without notice) and a nasty, NASTY rage when things don't go her way. Her children are on eggshells when she's around. And despite our history and the recognition of the trauma she faced as a child, I no longer speak to her. She is too far, far gone.
Zoso, as usual, nails it. Your kids are your priority, and you aren't doing them any favors if you stay in a marriage that is filled with anger and deception. My sister's children can now go to their father's place, and it's a refuge from all her craziness. Don't teach them that they have to settle for marriage scraps.
You can hold hope that you can have a new marriage with someone, maybe even your wife, a marriage full of love and respect, but you can't have that new marriage if you keep sending your wife the message that your current one is acceptable.
PS: Sometimes I feel foolish when I write that my sister is addicted to pot, even on this board, given the very heavy duty substances that are out there. With the public leaning towards legalization, it just adds another layer of second-guessing. However, I listened to a podcast not too long ago about a woman who was frustrated with her husband's pot smoking. If you don't have the time to listen, at least read the comments. When I heard the podcast, I felt some validation for the feelings that I had.
Dear Sugar, Episode 30: Is My Husband?s Pot Habit A Problem? | WBUR