You should consult with an attorney about your situation. However, I can tell you that the first step is to file for dissolution of marriage with children. You will have a status conference fairly early on, at which point you would need to seek a temporary orders hearing. At that hearing you would present evidence as to your financial situation (as shown on your sworn financial statement) and ask that the court make orders for him to leave the marital home and help pay for the home during the divorce process. You also have the right to ask for maintenance and child support if the children continue to live with you. Again, if he and you do not agree on where the child should be, the court would also make temporary orders regarding the children at the temporary orders hearing. This is probably not something you will want to do on your own. Get an attorney.
Nothing in this communication should be considered legal advice. Nor should this communication lead you to believe that an attorney-client relationship has been created. Only after thorough analysis of your case with you in my office can I provide effective legal advice on your specific issue.