I want a divorce but do not want to give my husband custody of my kids. Is there a way out?

It is not up to you to decide. You can state your wish to the Court though. The Court will take into account the wishes of both parents, as well as the child (if he is old enough to express his opinion), but ultimately the Court will take into account different factors and prioritise the interest of the child. This, of course, includes finances as well as future family environment. http://www.lawsociety.org.sg/forPublic/YoutheLaw/CustodyMaintenance.aspx