Um.. I gave my account to my friend (IRL) so he could play it on steam but the next day I see it is Permanent Banned??
Bans are not overturned and this is not the place to appeal them if it were. See the forum rules.
Regardless, YOU are 100% liable for what your friend did with your account. I'm sure he's honest and will tell you all about how his actions cost you an account. Hopefully he didn't get you ISP or MAC address banned.