How do I start to set limits? I can’t take it too much longer.
When she was violent before, what happened?
Do you have a safety plan for you and S8?
Can you tell us a little more about what your wife is like (is she diagnosed, does she work, is she suicidal, etc.)? There is a range of behavior with BPD sufferers. Maybe we can walk with you and share skills that can help things from getting worse. Even if you leave, it will help to know some key relationship and communication skills. The skills are not intuitive and must be learned (and practiced).
Gathering legal information is also helpful. You don't have to use it, but just knowing how things work where you live can make a big difference in how you hedge your bets and be prepared. Being in a volatile relationship means juggling a lot of seemingly contradictory possibilities, just in case things go off the rails.
How is your son doing? Is he showing any stress-related behaviors?
Do you have people in your support network? It's pretty common for people here to become isolated. Telling your story here, sharing as much as you are comfortable sharing, can be an important step toward taking care of yourself.
Glad you found the site
You are not alone.
LnL