Dizzy, dizzy, dizzy
In the meantime, increase your liquid intake.
Please note: I AM NOT A DOCTOR. If you want medical advice, talk to your doctor. Whatever I post, there is probably some surgeon or other health care provider somewhere that disagrees with me. If you want to know what your surgeon thinks, then ask him or her. Check out my blog.
I agree with the other posters: iron, possible orthostatic hypotension, and perhaps you need more water.
Another possibility is low sodium given you are dizzy from just sitting there and while you blood pressure isn't dangerously low, it is the low side of normal (the upper number...69 is great). An easy way to test this is when you feel dizzy lick some salt out of your palm and see if your dizziness improves. If you notice an improvement be sure to mention it to your doctor ...most likely your PCP. Surgeons are usually just the cutters and you follow-up with them for surgery-related issues...this may or may not be surgery related.
I have been having similar problems for the past 3months. Lots of fatigue as well. You may want to check out neurocardiogenic DynCorp or autonomous dysfunction. Salt and tons of fluid is the best way to deal with it. Unfortunately for me my blood work also is coming back with high autoimmune markers. A rheumatologist is my next step with hopes of getting some more answers. My surgeon did some research on the problem and presented a paper on it. Said about 10% have the problem with vertigo about 3months post surgery. He's the one suggesting salt and fluids as the best way of treating it. I get in at least 112 oz. A day. Also need to no so every afternoon because I get so fatigued and that makes it worse. Good luck and my prayers are for an easy quick recovery for you.