Want to Divorce Emotionally Abusive and Unstable Husband and Can’t

This is the second time I have ever posted here and need advice as to how to proceed. I (46f) and my husband (46m) have been married for 16 years and together 20. We have two children that are 11 and 9. Throughout the course of our marriage, he has been verbally and emotionally abusive. In addition to the hurtful and demeaning comments, our days for the past few years have consisted of yelling, punching walls, throwing things, cursing, coercion, lying etc. The family literally revolves around his moods and avoids his reactions if possible. Subsequently, I unbeknownst to myself slipped into depression and over the last decade have completely lost myself and have felt like crap. The eye opening event was I caught him in an emotional affair two years ago and haven’t been able to see him as I once did (perhaps a fictitious version of what I wanted him to be). I wanted to leave then and when I said I was doing so, he told me that he’d kill himself. So, I stayed. I started therapy, competed two iop programs and have regained confidence in myself. I also became aware of how toxic our life was/is and how unhealthy this all has been for me and will continue to be. I need to leave. My issue is that he has no one. He’s managed to push away all of his friends and has pissed off his sister and mother. I’m concerned if I leave that he is going to do something drastic, like hurt himself. Aside from his therapist, he has absolutely no one. I’m also worried he’s going to brainwash the kids into thinking this is all my fault. Ugh. I know what needs to happen, but how do I execute this with the most minimal effect? I really do love him; however I can’t be with him anymore. I’m ready to move on. There’s been too much that’s happened and I can’t go back to someone who has treated me this way for so long; but I want to stay amicable or even friends for the sake of our kids. How do I leave this man? Thank you for help!