3 sentences

1. 我觉得我再也吃不下了。

   wǒ jué​de wǒ zài​yě chī​bu​xià le.

   I don't think I can eat anymore.

   Source: OpenSubtitles

2. 我已经吃饱了，再也吃不下了。

   wǒ yǐ​jīng chī​bǎo le, zài yě chī​bu​xià le.

   I'm already full and can't eat another bite.

   Source: Dong Chinese Dictionary

3. 我已经吃得太饱了，实在吃不下了。

   wǒ yǐ​jīng chī de tài bǎo le, shí​zài chī​bu​xià le.

   I'm already too full; I really can't eat any more.

   Source: Dong Chinese Dictionary