I pay child maintenance, but I feel unappreciated and am often prevented from seeing my children. How do I stay sincere?

Keep paying maintenance as an act of worship and a trust towards your children, while claiming your visitation rights through the proper channels. The Prophet ﷺ said: “even the morsel you place in your wife's mouth” (Sahih al-Bukhari 56). If even a morsel for your wife is rewarded, how much more the provision you spend on your children. That reward does not depend on your ex-spouse's appreciation. Keep proof of every payment. For visits, propose a clear schedule in writing; if you are still prevented, ask the Syariah Court to set one. Contact your children through permitted channels, such as calls and messages, and never bring up the maintenance in front of them. Read the explanation in child maintenance.