You MUST - Document, document, document.
take photos of her being schizo / self harming / any behaviour deemed anti social.
Note in a diary any time / date she goes off her rocker. Even if it's only a month or 2.
Note times and dates of when she leaves the house to go visit her cheatwhore.
Document document document for 2-3 months.
Make a list of everything you've purchased while with her, attach any receipts you've got and note it's current value (immacualte / worn etc).
Make a list of any money you have given her.
Then - take everything that is rightfully and provabley yours and lock it up in someone else shed and give the keys to a mate. That way you can't be accused of using it / devaluing it whatever.
Get a lawyer.
Write her a letter, not tell her, that she is to move out and take all her posessions that she paid for out of her income only give her a copy of the list of the things jointly paid for and tell her you will see her in court. Hand it to her. Note the time and date.
Wait 48 hours and change the locks. Document any bad behaviour, things she takes that are jointly owned.
Don't get into any fights, just let her bury herself.
Go to court, point out her documented behaviour, point out her 'taking or rather stealing' of things jointly owned, point out her cheating and provide evidence, do not get into battles or fights with her, just sit back and make her look like a lunatic.
Point out any self harm scars, point out and diagnosis of bipolar disorder. Suggest that if theres any doubt that the court is more than welcome to make it's own assesment.
Ask the magistrate to bear in mind the difficulties that this has put you through in the last however many years, and how you have diligently pursued the relationship, with every effort to improve her health and well being.
Point out that you have been repaid by her cheating on you, present times and dates if you can, and before she can argue with you, say you are prepared to name the person and have them summoned as a hostile witness and to force them to testify under oath.
Present it all in an indifferent, unstressed, open and honest way.
Sit back, watch her scream, rant, rave and threaten.
Watch the judge award everything to you that she didn't specifically pay for out of her own income.