Both my children turn 18, my ex husband said he does not have to pay any more. My 23 year old went to college he did not help or give support any mor

That depends on whether you have a written agreement, or a court order for child support.  If so, the terms of that agreement control.  If there is no order saying he has to continue to support your adult children through college, then he does not have to do so. Child support normally ends when the child turns 18 and graduates from high school.