Well, I can't tell you how you will do, because I don't have the kind of information or detail that would be necessary, but I can say that a practice test is not so much about the score as it is about getting you ready for the experience.
Just as a sample, here are my practice results and actual GMAT results:
Barron Diagnostic, December: 550
Kaplan Diagnostic, January: 650
Princeton Review Diagnostic, January: 610
First hard-copy GMAT practice, February*: 630
(*
MBA.com sells these for $25 each, old actual GMAT tests no longer in use)
First Kaplan CAT, February: 650
Second hard-copy GMAT practice, February: 670
First Princeton CAT, February: 690
Second Kaplan CAT, February: 630
Second Princeton CAT, February: 720
Third hard-copy GMAT practice, February: 760
Kaplan full-scale practice GMAT, Feb 26: 610
Actual GMAT, March 14: 730
Looking at the practice results, only one of them was higher than my actual score, but what I was doing was learning from them, putting together error logs to see what I was doing wrong, and gradually improving. When it was time, I had worked the most where I needed the most work. Did you do that? I can't tell from your post, but if you did, you'll be fine.
The main thing now is, relax. Whatever is going to happen is on the way, and your best tactic now is to be ready physically and emotionally. It's a 4-hour test in unusual conditions, so be sure to get a good night's sleep, take some healthy snacks (
I took 2 apples, a cola, and a bottle of water) for your breaks, and remind yourself to relax, because that will get you your personal best results.