Subject + 感到 + 失望
The adjective 失望 (shīwàng) means 'disappointed' and describes a feeling of letdown when expectations are not met. It can be intensified with adverbs like 倍感 (to feel doubly) or 非常, and can also function as a verb meaning 'to lose hope in something'.
考试成绩出来后,她非常失望。
Kǎoshì chéngjì chūlái hòu, tā fēicháng shīwàng.
After the exam results came out, she was very disappointed.
别对他太失望了,他已经尽力了。
Bié duì tā tài shīwàng le, tā yǐjīng jìnlì le.
Don't be too disappointed in him; he already tried his best.
结果让所有人都倍感失望。
Jiéguǒ ràng suǒyǒu rén dōu bèigǎn shīwàng.
The result left everyone deeply disappointed.