What's the law about property in a break up?

I have lived with my partner in a house in her name for 10+ years and now she wants me to move out. I have paid 1/2 of the mortgage, or in her words "rent" since we have been living together. I have also paid 1/2 for one of the cars we have (in her name), and many improvements on the house including new windows (I paid 3/4), flooring, carpeting, the yard, patio, railing, stairs, an awning and other things that would all have to stay with the house. Wisconsin does not have a common law marriage law anymore, but am I entitled to be paid back for all these things if I won't be living in that house, especially if she says that I was just a "renter". We do not have a lot of the paperwork of who paid what, but she admits to the fact that I did pay for a lot of those things I mentioned before. We have 2 young children together (4/-1) and I still love her and want to somehow work things out, but she has been real nasty to me at times. Does anyone know what the law is about that, I am not a wealthy man, and lawyers are not cheap.