Hey Joel,
Please read the sticky. You need to be wearing shoes when you squat.
It sounds like you tweaked your back, a very common occurrence in the weight room
The Squats look fine. You need to order weightlifting shoes and a belt.
Your anthropometry puts you at a slight mechanical disadvantage with the deadlift but I think a few adjustments will help:
1) Narrow your stance a bit and point your toes out a bit more. Shove your knees out a little more at the bottom. This should allow you to set your back a little better and get your shoulders above your hips. Also squeeze your chest up extra hard. Try to show your nipples to the wall in front of you