I have waited to see more of the story before I made a post.
She IS bi-polar. Yeah, they all are a little, but some, many, are bi-polar and everything that happens is all your fault. There is a lot more of this than most people give it credit. Even if she agrees to actually getting therapy, which is rare because they tend to know they have a problem, but they won't do anything to make it better, she still has to go thru a lot of therapy, take medication, etc, and they usually don't stay with it. It will still always be there, although she may be some better things will never be right with someone who is not on a high functioning level. Self medication; drinking, drugging, will make any discussion even more difficult.
She has many psych issues, and the more of them she has the lesser of a chance that she will get past all of them. Paranoia, delusions, Obsessive/compulsive, schizophrenia; all these things will come out more and more, especially after childbirth. You will always have this between you, and it will take a tremendous toll on you. This assumes that they aren't also abuse issues buried deep down; because that is even more crap to try and contend with.
I've been thru this with someone I spent half my life with. I was helpless to watch her go absolutely crazy. My ex jumped out of the moving Tahoe 1 mile from home, heading up to the lake for the weekend with the boat, after staying home from work, washing both the Tahoe and boat, and loading them up for weekend (manic), because I wouldn't pass a corn harvester that would only be on the road in front of us for less than a mile, because dust was getting on the truck. With my 8 year old watching her from the back seat, she leaped from the moving truck in shorts and a tank top onto severely eroded asphalt. They don't know what they are doing ten minutes from now and they don't know what they did ten minutes ago, in this state. My son and I went up north anyway, and she showed up the next day like nothing ever happened. totally oblivious to the bandages and bruises, then later that night she went back into wack mode.
There are scores of similar stories. I stayed because I had been with her half my life, and had a child with her, so I tried everything to make it work. Once when she got violent with me, I pushed her away several times. She called a friend and said I was beating her like a thug, and the cops come and take ME to jail. For absolutely nothing, but that's how it works. Charges were dropped but the stigma remained to come back at me during divorce. This put me out of the house, without recourse, as soon as she filed. So YOU FILE FIRST.
Counseling was a disaster. She claimed it was all me, so they got her to the point that she would file. I STRONGLY voiced my belief of a physiological problem but they never gave it any credence. It destroyed my life, really hurt my son's life, and she has yet to get any type of help.
You cannot live your life for your family, friends or anybody but yourself. I tried intervention, family Dr., getting her to try Zoloft, everything I could think of, but nothing will get them to help themselves if they don't want it.
The bottom line is, cut your losses now, and GTFO. Protect your assets by moving them to family or good friends, because once they go into divorce mode, amicable goes out the window and her friends will have her try to take you for all you have. Get all titles into another name. Hide cash because you will need it to start over with utilities, rent, deposit, etc, etc, etc. Any soft heartedness will be taken advantage of, so make careful plans and don't fall for 'meet me for lunch so we can talk'. It is a lawyer's ploy to get your stuff.
Been there, so listen. Good luck, it will test you like nothing else ever will.