Leave. If he isn’t willing to seek treatment leave. What he’s done to you already is stalking, harassment, false accusations, abuse, and manipulative behavior. Save what Facebook or social media information you can and make a plan for having an EPO put in place. He won’t be a good parent if he is willing to refuse treatment or even a diagnosis.
If your willing to make excuses for poor behavior now, don’t expect your kids to love or live with you long term. I’m being blunt but it has to be said.
My siblings got full time jobs and worked through school to avoid coming home thanks to my brother, and while we are still close to my parents because they are not in denial, that it not the case for everyone. I’m hoping now that my brother is permanently hospitalized that I can get a real job again and get OUT of any profession that requires caretaking. Just because I know how to do the job well doesn’t mean I want to, especially for someone who has no mental capacity to judge how badly they would be without you. Babies, at least, will smile and be happy when you care for them. A person with mental illness does neither. As another side note, my mom has bipolar disorder that she has fought tooth and nail to be stabilized and has had a fulfilling career BECAUSE SHE IS TREATMENT COMPLIANT. If she or my father were not cognizant of that fact it’s another reason that your future kids can and will be rightfully taken away. While I understand you are being kind, and that is commendable, we have one life to live. Being in denial makes everything about the situation worse. It puts you and kids who have no choice about the parents they grew up with into danger. It will make it so that they will be flung to the fore winds of family members who will abuse them. To make a long story short foster parents are awful. Family members who foster are even worse, and the fact that they can lie while having state social workers waltzing through the house ignoring signs of carer abuse for biological and non-biological kids they’re being paid to take care of is the worst thing of all.
My mother and my brother cannot choose their illness, but only one of them has any relationship with us anymore. This is a game for the long haul and you must always be ready to run and take care of yourself and the kids completely independently if you don’t want them raised by foster care or worse. Children can grow to hate their parents and a child should NEVER be made to be in a situation that you had complete control over when it comes to leaving. Secure your financial independence and run. There are other fish in the sea and you owe him nothing if he will not seek treatment.