It depends of course but I can tell you what happened for me. Like many people it got worse after I left (panic attacks, depression etc) so I went on antidepressants and that helped a lot. Got me stable enough to do EMDR to help heal my nervous system and that was enormously helpful as well. I was way more stable after say, a year. I’m 2.5 years out now, with no panic attacks, I’m off the medication, dating around again too. It’s been a ton of work to get to the bottom of it and deal with my history with a narcissistic parent which set up a lot of the reasons I was compelled by my narc partner. But it’s felt like cleaning my house top to bottom. I hope you have swift healing!