overtax  
verb [ T ] uk/ˌəʊ.vəˈtæks/ us/ˌoʊ.vɚˈtæks/
  (MONEY)      
  对…征税过重,对…课税过多
to demand too much tax from someone or to put too much tax on goods
  I've been overtaxed this month. 这个月让我缴的税过多了。 
 Food should not be overtaxed. 对食品不应该课税过重。 
   (DIFFICULTY)      
 使负担过重,使超负荷工作;对…要求过高
to cause to feel tired or confused as a result of doing too much or doing something too difficult
  Remember you've been ill, and don't overtax yourself. 记住你在生病,别劳累过度。 
 This problem is overtaxing my brain. 这个问题真是把我难住了。