Thoreau,
I think the pharmacist has it exactly right, but with the tetracycline, it's hard to know what food items contain dairy, so I just take it on an empty stomach to be safe.
You have age on your side. I'm 49, so I'm not as tough as I used to be
I'm sure you'll be fine, but don't be surprised if you feel crappy for a few days before you start to feel better.
As for me, I'm on day 12 and starting to feel really good! Only gone 3 times and it is into the evening hours now. I was going 12+ times before the antibiotics. This has really settled my guts down big time.
Best of luck and post some updates if you can.