Don't listen to this guy. US prisons are NOT like what he said. They aren't much at all like any of what the media portrays them to be.
You DO NOT have to get ganged up to be protected.
The most important thing is to not go in with some sort of attitude like you have something to prove. Be yourself. You will find many people that are in similar situations as you.
These days in this country, jails and prisons are FILLED with non violent folks like yourself that simply made a mistake and got tangled in the system. In fact, from what I've seen, there are FAR more GOOD people in jail, than BAD people.
Stay positive.
+1. 6+ yrs for me. And you can hit the ground running when you get out, as long as you keep your head straight and plan for that.
Time sucks, but you'll make it through and be ok and life will still be here for ya mostly the same as it was.