How do you say

My new sofa is very comfortable to sit on.

..in Chinese?

我新買的沙發,坐起來非常舒服。

wǒ xīn mǎi de shā fā , zuò qǐ lái fēi cháng shū fú 。

How do you say "I wore this shirt for just a month and it’s gotten smaller." in Chinese?