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。

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。