Bombed official GMAT prep CAT #2

Took a completely cold official GMAT CAT as a baseline three months ago and got a 590 (36Q, 35V), target score is 700 so obviously have some work to do particularly in Quant which I knew was a weakness. I have been studying hard the last three months about 15 hours per week consistently and recently felt like my preparations were really going well. Last two CATs I took about 5 and 7 weeks ago mostly for timing practice I got:

630 (43Q, 34V) - Kaplan CAT
600 (42Q, 32V) - MGMAT (something about MGMAT verbal really threw me off)

This past weekend feeling good I decided to take official GMAT practice test #2 and completely BOMBED with a 570 (35Q, 34V). I was legitimately shocked to see this score as I thought I was cruising during the Quant portion and 90% of my studying is devoted to Quant. I'm at a complete loss right now and really discouraged that after 3 months I've somehow gotten a worse score than when I started and knew nothing. When I took my baseline CAT I couldn't even attempt half the Quant problems, but on the recent one I knew how to approach and solve probably 80% of them and only got 10 wrong. Of those I got incorrect at least 4 were just silly mistakes.

I missed 3 easy questions in the first 7 to start and after that never seemed to get any harder problems, it's almost like the test stopped adapting even though I had multiple streaks of several questions in a row correct - it just kept giving me easy problems.

Really feeling discouraged and bewildered here, I know Kaplan and MGMAT aren't the real thing, but I've read that MGMAT quant is typically harder than the real thing so I expected something at least in the low 40s. Hoping it was just a fluke and I bombed and/or crumbled under the pressure. Admittedly I was feeling a little nervous, made careless mistakes I usually don't and my mind didn't seem as sharp as I would've liked.

Anyone else just unexpectedly bomb? Just looking for some words of encouragement, feeling pretty frustrated.