Complicated

Afternoon everyone. My first time on here and first post.

I appreciate most divorces are complicated and hopefully my scenario isnt too out of the ordinary but I will try and keep it short whilst giving as much detail as possible.I met my wife at the end of 2013. She had two children to her former husband whilst I have none. I owned my own house whilst she was renting.I officially moved into her house around the summer of 2014 and rented mine out. I sold my house a year later and used the funds as a deposit to jointly buy a house with my wife. My wife didn’t have any money to contribute – when she and her previous husband divorced, she accepted a settlement of £6k!The house we bought, we carried out a huge renovation which included my wifes parents converting the lower ground floor of the property into a granny flat. Her father has a serious illness/disability so it made sense to help them out if we could. They paid the costs of creating the granny flat.They don’t pay any rent, and just contribute £400 a month to the bills and have no legal right on the property.My wife and I got married a year later. She has never worked full time, even though I have often encouraged her to especially as her children became more independent – they are now 15 - and given the pressure I felt in being the earner.So in effect, I have been financially supporting my wife, her children and her parents. Because of her fathers condition, the heating is on all the time and I am currently paying £461 a month in gas and electric and this is due to go up, albeit, thanks to the cap, not as bad as first projected.In March, due to various reasons, my wife decided she wanted to take a break or trial separation. She continued to live in the house, but in a separate room. To me, we should have been working at our marriage whilst still under the same roof, but she didn’t want to even try until she had moved out.Up until a month or so ago, she and the children were still in the house but her behaviour was becoming more erratic. She had for a few months been staying elsewhere. Starting one night a week, and then maybe two, and then three…Id had enough and decided we were never going to sort things out. SO we had a big fall out and she moved out and I found out that the children had gone back to live with their dad full time.Anyway, I have since found out a few concerning things. That my wife and her 15 year old children were openly using drugs with each other. I had smelt cannabis, prior to our ‘trial’ separation, but my wife told me it was just one of the children burning an incense stick. How naïve of me to believe that.Ive also found out from a parent of one of the childrens friends that my wife got one of the daughters to snort cocaine. This in our kitchen! Not that it matters where it was, but it just feels a massive lack of respect for what I have done for them. Social Services have become involved hence the children being back in the care of their father. (I only found this out at the weekend)Also, my wife had allowed one of the childrens boyfriend to share the same bed, prior to her 15th birthday! Of course I didn’t approve, but my opinion was worthless.Theres a whole lot more I could tell you, but you probably get the picture.So…I am in the process of employing a solicitor. I am not particularly bothered about getting a divorce right now, but I certainly want to get a financial settlement sorted to protect my interests.From my point of view, the simplist thing to do would be to sell the house. But that would leave her parents homeless as their life savings are in the house.The house is currently worth about £370k with £196k left on the mortgage. I used around £46k of my own money as deposit to buy the house.I don’t deny my wife is due some money but on the flip side, her behaviour disgusts me and I think I’m only touching the tip of the iceberg in what I have so far found out. Given how I have supported her, when she has been too lazy to work, her children and parents, I am loathe to agree to an equal split.Anyone got any thoughts on a) the in law situation and b) what would be a fair settlement to my wife?