Head/Ear Congestion During Workouts? {also: squat form}

Hey everyone,
For the past two strength workouts I've been experiencing what feels like head congestion or ear pressure sort of. If you've driven up the Rockies you know that vague sense that maybe your ears need to pop but there's not enough pressure yet (not dramatic like an airplane). Also similar to a head cold when it's just in your head not your nose and throat. It starts after I get into my workout and sometimes I feel light headed as well. I'm doing weights but nothing extreme; starting with Body for Life. I thought I was going to pass out doing 8lb dumbbell shoulder presses, not from exertion but because of this odd symptom. Has anyone expeienced something similar, and what did you do?
I haven't been ill. I do have a weird bump in my chest that I'm not sure if it might be a rib going funky or what, so I'm going to see my chiro next week if I can. There's a recent history of breast cancer in my family (mom; thankfully recovered) but this isn't really in the breast tissue so I think it's something else. It's hard like a bone but only on one side and a couple inches in length.
FINALLY, I was doing squats to work my quads, but I mostly feel it in my hamstrings. Does that mean I'm doing it wrong, or does it work both and that just happens to be my weaker/more sore area? I stick my bohunkus out behind me like I'm supposed to...
Thanks for helping a newbie.
~Mollie
Started PB on Monday, June 4. I'm focusing on my health in 2012, including taking natural supplements, zumba and strength training, regular church attendance and studying the Bible, spending time with good friends, and reading more. I want to see what health milestones I can achieve this year!
Starting body fat - 41%
Starting weight - 170 lbs
9/4 body fat - 33%
9/4 weight - 150 lbs