How do I protect my retirement in a divorce when I earn more?

The best advice I can give you is to consult with an experienced family law attorney. The general rule with community property (things you need to share with your husband) is that if it was acquired during the marriage (between the date of your marriage and the date of your separation), it is presumed to be community property. Your retirement account, if you contributed to it during the marriage, is one of these things that contains community property. If you started working and contributing during marriage and your separation is recent, it's likely 100% (or very close to that) community property. If you started contributing to your retirement before marriage, then your retirement has both a separate property component and a community property component., Your best bet is to hire a QDRO attorney (Google that, and lawyers who do this type of work will be shown). Tell them you have a retirement plan to divide. The type of plan you have (IRA, 401 (k), defined benefit, etc.) will determine how simple (or not) it is to divide. The best way to "protect" your retirement is to determine the community value (you will likely need an expert to do this) and then see if you can afford to buy out your husband's interest in it. For example, let's say your retirement is worth $ 120,000, and you have a house with $100,000 in equity. In that instance, you could keep the retirement, and your husband could keep the house. That would be an equal division of the community property, which is what the court is supposed to do. 

This type of property division can be complicated, so if you can afford it, I highly recommend you consult with a family law attorney to help you navigate these waters. Best of luck with this.