I love her kids but she is ruining my life

I currently provide for my girlfriend and her two boys. I've raised them on and off since birth but for last two years they live with me in my house. I would do anything in the world for those boys. Anyways for the last year she has been addicted to xanax and adderall and Dr's just keep perscribing it more and more. She always runs out and then steals money from me to get more and its led her to make many shady friends who have also stolen from me. Its killing her body she's always getting pneumonia and going to ER, she's been arrested multiple times and now has no license and can't work. I've enabled her so long hoping she would get better because I have no claim to the kids they aren't actually mine even though I care for them and they call me daddy. I know kicking her out is kicking them out as well but its gotten to the point where I'm ruined financially, my side business is in shambles, and I just can't find any happiness. Any advice from anyone out there?