iPhone 5s - Home Button And Fingerprint

Hi. My iPhone 5s Home Button is not working. It is clearly clicking as I can hear it. It works every 1 in 20 times but never consistently. I have setup assistive touch but i would like to fix it for good.

Also, I cannot setup touch ID on my phone or a friends. But when my friend tried to set his finger on my phone it works?!? Is there something wrong with my thumb?

Thanks,

Amir_1