O no, that must be hard.It sounds like you are not feeling home in your own house at all.
I would be disappointed , too.After all your wife has promised to put your relationship first and only help out for a few month.
Whereas I totally understand that she wanted to help her pregnant young daughter in that difficult situation I don't understand that she doesn't motivate her to find her own place now.Allowing her to stay unlimited is really affecting your marriage and goes far beyond offering general support.
I couldn't do it either...I have three children and one stepdaughter- the youngest is 8- I have totally outgrown the baby stage (although I adore babies and toddlers).And I think it is ok to feel like this- nearly everybody reaches this stage sometimes.
What I am also concerned about is the reaction of your wife when you tell her that it would be a good time for SD to start looking for a place.She seems very agressive and defensive and does totally not consider that you are in this far longer that you BOTH agreed to.She also puts the blame on you, virtually saying that you are a horrible person because you kick her child out.Allover it sound very unfair and I can imagine she is so extremely defensive because deep down she knows she is unfair and instead of admitting it and having to do anything about it she blames you and makes you the "bad guy".
It sounds like you don't cope with the situation very well and feel depressed and unhappy.
It is really hard to advise what to do, but I think to break out of this vicious circle of accusations and blame I would maybe consider even some marriage councelling.Maybe you could also try to organise a special dinner or weekend away that you two can use to sort things out.Maybe if she feels less threatened and feels that you are not accusing her of breaking her promise but nevertheless would like to see a sooner solution than waiting 4 years, she would be more open to look for opportunities to help SD to get on her feet and move out.
However if you inspite of trying everything with your best intention feel that she will not looking for compromises and insist to go on for 4 years I would think that the marriage is not so important to her than it should.If she really doesn't want to see your side you may need to create some distance to keep your sanity.

I think you are in a really difficult spot now. I don't think that your SD is going to leave any time soon, especially since she wants to stay until she graduates. And graduation does not mean that she will necessarily want to/be able to leave then.

I do not think that your wife is going to make her daughter and grandchild leave. But, I think you need to sit down with your wife and tell her that this is NOT the life you AGREED upon. Your wife broke her promise-that is the bottom line here. Clearly, her daughter's needs are more important than your needs.

I know you feel alone and extremely sad, not only for the fact that your home is not your home, but also because your wife did not do as she promised.

I know you do not want to be divorced again, and you obviously love your wife. However, love is sometimes not enough. YOUR happiness is important, too. You are still young; is this what you want?

My husband and I were married almost 6 months ago. Before we married, I made him promise that his adult kids would never move in with us. They are terrible people, we live in a very small home-this can never happen. 2 of the 3 really want to come here, and the more I think about it, I think their reason is to break us up. Also, their mother is pushing for it, because she is tired of them lying around at her house all day.

If my husband breaks his promise and wants to move one or all of them in here, I will be GONE. Also, if he decided to support them, I am out of here, as I also made that clear-we are not their bank. So far, he is saying no. But, if he changes his mind, we are over. And, I, too, will be divorced for a second time. As much as I love him, and as much as it would pain me terribly, I know where my tolerance level ends. I think you do, too. If your marriage does not survive, do not look as this as a failure on your part, because it is truly a failure on your wife's part to put her husband's needs first, and to stop enabling her daughter.

If she was able to have a baby with some random guy, she sure can take care of him. Where is the baby daddy?

{{{HUGS}}} messy situation indeed!

In my opinion..I think guys come to their senses easier then women do and your wife is putting her emotions first here. How much can you or are you willing to tolerate is a big question that you can ask yourself. You need to be fair to yourself and consider what you want for your future.

I was married once for 9 years and was not happy until we got divorced. I thought that I felt alone but remained married to avoid being alone..go figure!!!

Foxie gave really good input and advice and I believe that she knows what she is talking about. She is one of my favorites on this site and I have taken a few pages from her.

Remember what you and your wife agreed to before your marriage then sit back and look at how things are now. You honestly are not being unreasonable at all.