What do I need to do to get full custody of my son?

Florida Statute 61.30(11)(c) provides that "a parent’s failure to regularly exercise the court-ordered or agreed time-sharing schedule not caused by the other parent which resulted in the adjustment of the amount of child support pursuant to subparagraph (a)10. or paragraph (b) shall be deemed a substantial change of circumstances for purposes of modifying the child support award. A modification pursuant to this paragraph is retroactive to the date the noncustodial parent first failed to regularly exercise the court-ordered or agreed time-sharing schedule." You will have to file a Supplemental Petition to Modify based upon your ex husband's failure to exercise court ordered timesharing.

Mr. Feuerstein is correct. You are not bound by any previous waiver of child support. The lack of contact over the past year is the status quo and he should have a hard time arguing that he should now get more time. He will have to pay child support based upon having used less less that 73 overnights per year and based upon your respective incomes and the cost of day care and health insurance for the child. You need to consult with a lawyer on how best to proceed.