Hi,
you remind me so much of myself. I was stuck at exactly the same score and that's also what I got on my first GMAT attempt in April after studying for 3 months straight. 580, (Q39, V31).
I remember it being extremely frustrating because I had invested SOOOO much study time. And by the way I had the same results on
MGMAT as I did on the original practice exams. For me it didn't make any difference although in hindsight I do want to mention that the math seemed a little bit harder on
MGMAT exams. (not a whole lot though!)
I then added some new prep material including EmpowerGMAT and took the exam again in July. This time 630. It may not seem great but I was the happiest person in the world when I finally started scoring above 600.
I am still studying and added tutoring sessions to my prep and yesterday I just signed up for the GMAT again to be taken in September. Hopefully this will be the last time. I am getting tired of the GMAT. At some point everybody will face a burn-out.
Don't give up yet!
It is very upsetting to see how hard some people (like me) have to study to see minimal results and I really don't have great advice for you I know.
I think you may want to add another online course or tutoring. You said you just subscribed to math revolution. Maybe that will help you break through the barrier. When you are stuck try something new and practice practice practice.
For my part, I have given up hope for a 700 but would be extremely happy if I could add just a few more points to my current score.