Please Help...

I'm in a lot of stress now mainly becoz I'm not quite getting close to 1500

for reasons this March 14th will be the last possible SAT for me, and I really wanna score the best I can it was going all good, until yesterday I was getting around 670 in R&W and above 750 in maths improving quite a lot dy by day, for example I got 1250 first, then 1350, the 1380, the 1430

but now I am literally depressed...after practice test 7 I jumped to test 11 and got 590 in the R&W section idk...is it really tougher than the other tests ? tbh I was hardly keeping up on time the questions were a lot lot lot more time consuming and harder to comprehend at the same time, did a lot of mistakes with the time pressure...

idk what to proceed with now what are your thoughts on this ?