how do i protect myself and children against my spouse trying to not give us anything from his lawsuit

Here is the law regarding the distribution of marital property in Indiana: Indiana is an equitable distribution state. The court shall presume that an equal division of the marital property between the parties is just and reasonable. However, this presumption may be rebutted by a party who presents relevant evidence, including evidence concerning the following factors, that an equal division would not be just and reasonable:

• The contribution of each spouse to the acquisition of the property, regardless of whether the contribution was income producing.
• The extent to which the property was acquired by each spouse:
  1. Before the marriage.
  2. Through inheritance or gift.
• The economic circumstances of each spouse at the time the disposition of the property is to become effective, including the desirability of awarding the family residence or the right to dwell in the family residence for such periods as the court considers just to the spouse having custody of any children.
• The conduct of the parties during the marriage as related to the disposition or dissipation of their property.
• The earnings or earning ability of the parties as related to:
  1. A final division of property.
  2. A final determination of the property rights of the parties.

If the court finds there is little or no marital property, the court may award either spouse a money judgment not limited to the property existing at the time of final separation. However, this award may be made only for the financial contribution of one spouse toward tuition, books, and laboratory fees for the higher education of the other spouse. The court, in determining what is just and reasonable in dividing property under this chapter, shall consider the tax consequences of the property disposition with respect to the present and future economic circumstances of each party. [Based on Indiana Code Title 31 - Article 15, Chapter 7-5 through 7-7]

I would not sign anything without speaking to a family law attorney near you.  I realize you are in Illinois and your husband is in Indiana, so there may be some conflicting laws involved as well.