Hi,
sounds as if you have 3 good reasons to give it another try:
1. You were ill today and hence could not show your skills.
2. You sent today's score, which is worse than your first one, to your target universities.
And the most important one:
3. With your 740 in GMATPrep, you have indicated that you could achieve a 700+. Assuming you do not get a couple of questions you already know, GMATPrep is a good indicator of what score you can achieve in the actual test.
I understand that you require time for your essays. However, it seems that you do not necessarily need to improve your GMAT-related skills. You are already on a high level, so you probably don't have to study a lot in case you retake soon (in fact studying too much might harm your motivation). If I was you, I'd keep on practicing (but not too much) to keep the current performance level and I'd surely challenge the GMAT once again.