I am sorry that you are having to go through this.
This is hard for everyone and as you said, even though you are an adult you want your family to stay together.
In reality, your parents have their own lives, their own needs.
The are still young and are allowed to find happiness. Obviously together, they are not happy.
Don't you want them to be the happiest and best they can be?
Things change and we have to learn what our new normal is going to be. My home is not the building we are in or the house I grew up in, it is when me, my husband and daughter are here together.
My parents were divorced when I was young, and it was devastating, but when I look back I realized they were terribly unhappy. That does not diminish the love they had for me and their fondness for THOSE memories.
But now they have found their happiness in other ways.
My father moved to a totally new place for a while, it was exciting to see how he changed his attitudes. He was more content and settled.
My mother became more active in the community, she started a business, she found new friends, she travels (my father hates traveling) she is now remarried after 18 years of being single.
My father was remarried 2 times, his wife is an amazing woman and has been a very special addition to our family, his 2nd wife is also an amazing woman and still in our lives.
When they are happy, it makes me happy.
Your father is going through a difficult time. he may be confused, he may be stunned, but he is probably a strong man and is going to find a new strength. He can take his portion of the sale of the house and maybe find a nice condo, or a small home.
I encourage you to go to a therapist and talk out all of your TRUE feelings.. They are there bubbling under the surface and soon are going to begin showing themselves in all sorts of surprising ways. This is normal and good, but be sure others around you are aware of your feelings not being directed at them..
I am sending you a big hug and I promise, it will get better.