Sorry to hear about the trouble.
IMO no woman is worth you losing your health.
No woman is worth going you to jail.
No woman is worth you hurting/shooting/running over someone else.
You are lucky she did this now. This may seem strange but you got off easy; it would have been much more difficult and expensive to get rid of her cheating ass if you were married or had kids.
Enjoy your freedom and find yourself a new/better looking/richer/younger g/f.
Those two deserve each other if they have that little integrity; especially since she obviously planned you to find the two of them (imho). As noted above, they will cheat on each other in time.