I definitely agree that a 7.0 speed is very fast for a beginner! I've been running casually for ~2 years now (mostly on the treadmill, occasionally outside), and my average speed is still around 5.5-5.7mph! I do occasionally push it up to 6 or 6.2 for a short bit, but I can't even fathom being able to run at 7.0 for any length of time without feeling like I am about to die, and I can cycle for a long time without difficulty. I know many women run much faster than my speeds, but you are a beginner, so sloooooooooooooow down!

I agree with the suggestion of Chi Running -- I read the book when I started running and found that it helped my form and comfort while running a great deal.