Hey, there will always be bad days for GMAT exams and you will always have next time to improve your score. I think there are other ways you can improve your quant score. Mathrevolution probably owe you a refund as well (so don't forget to send an email on it). I started of with a Q37 as well and I can see why you are frustrated with the score.
The surprising thing you said about your debrief is that you have already gone through a lot of material for quant and see no score improvement. I have some suspicions as to why so it would be great for you to clarify some of it. I'm sure you can get a higher quant score, I still stand by the fact that quant is a practice game and the more
right practices you do, the more you will get correct.
Mathrevolution aside, do you have great basics for quant? (For example, fast and accurate at basic addition, subtraction, division, and multiplication). I remembered that Q37 score for me was due to lack of basics, I keep on getting ridiculously easy questions wrong. I couldn't compute percentages and had a hard time dealing with estimation questions because I couldn't even do long division. Maybe you should consider redo-ing math basics and get to understand why math questions work the way they work. I know MR is super focused on two particular math strategies and the course is on the heavy side of remembering and not understanding.
I recommend
MGMAT for quant boost. It definition helped me get from Q37 to Q47.
Second question would be, how were you doing your
OG questions? Did you go through each answer and check how you got them right/wrong? I feel that a lot of people miss out on reviewing their progresses. It's not really about getting the questions right the first time but it's about knowing why you got something right. If you don't know why/how, it means that you can replicate the same process. GMAT is a game of skill and not luck.
What's your speed? Have you worked through improving time management on the GMAT? You do not have to do every single question to get quant higher than Q47. You can get 25% of the answers wrong, meaning you could also guess some and use the time you have left to work on other questions you judge as easier to do.
I think you have a shot at getting better score. Don't give up. If you do, this will be the only score you have. Better days are ahead my friend.
Good luck!