1345Marine, I know it's overwhelming to think about, but you will get through this and it is possible to extricate yourself from this marriage without becoming destitute or abandoning your kids. It will just take you a lot of time and planning.
First, consult with a lawyer. Money might be tight, but some offer free consultations. And as expensive as a divorce might be, it may be cheaper in the long run. If you have to pay alimony, it will be a fixed percentage based on your income and other factors; the law does not require you to pay for your ex's food, lodging, and entertainment for the rest of her life. You're probably spending more money remaining married to this lazy, lying, leech than you would be if you were divorced.
Also, your kids are old enough to decide which parent they want to live with, exclusively or primarily. If your kids are living with you ≥50% of the time, you will probably have to pay little if any child support. But again, a lawyer could give you a better idea of what to expect.
Second, as The1stWife said, do not move out of your home. Depending on your jurisdiction, this could be considered abandonment and may have implications on child custody or use of the home in the future.
Third, document EVERYTHING. Write down all the chores you do and how often. Write down how often she sleeps every day, how much alcohol she drinks, etc. Write down everything that you do for the kids. This is how you can prepare yourself to get sole or primary custody.
Lastly, I'm with Tushnurse in that my jaw hit the floor at the idea of your wife, of all people, becoming an RN. She's the last person who she be allowed access to drugs and responsible for the care of vulnerable patients.
Her schooling should not factor into your decision making or planning whatsoever because there's no way that she will finish the RN program, even if you remain married. She's already flunked out multiple times and is screwing up at the little CNA gig she has now. She doesn't have the drive, motivation, resilience, or emotional stability to complete such an intensive program, let alone practice in the real world.
However, you are correct that you have been enabling her to coast by in life. Perhaps the best thing you could possibly do for her is force her to stand on her own 2 feet.
[This message edited by BluerThanBlue at 3:35 PM, Wednesday, February 21st]