I bought a house and put my then girlfriend's name on it as well (first mistake). We thought we were going to get married but that obviously did not happen.

I bought the house for $30,000 and put in another $15-20 thousand of my own money. She did not put any money towards the house. Her brother does construction and helped with repairs. I paid for all materials.

I have been trying to settle things with her and offered to pay her brother a reasonable amount for labor and give her $5000 dollars on top of that. She responds by saying that she wants $20,000 to take her name off, or that we sell the house and spilt the profit.

I do not want to sell and she has no basis for anything close to $20,000.

My questions are is there anything I can do in my situation. The house is in both of our names and she also refuses to split property taxes ( am I able to sue her and get half?)

Since then I am currenltly living in the house and she has moved out.

I live in Michigan if that helps

You are going to need to retain a Michigan attorney and sue her for title to the property.

One possible theory that your lawyer might want to consider is a gift in anticipation of marriage (such as an engagement ring, for example). If, under Michigan law, such gift is revocable if the marriage doesn't occur, you may have an case.