You're almost there!
For the questions you've gotten wrong in the sciences, make sure you go back and restudy the concepts for each of them, asking yourself why you got those questions wrong. Was it a calculation mistake? Maybe you got a reaction confused with another? On my actual exam, I found that I scored 1-2 points higher than my BC prac scores, so keep your head up!
For PAT, keep on practicing with the generators on BC! It will pay off! For reading, have you used the same strategy each time you've taken a practice exam? If so, maybe try a different one to see if you score higher. What worked best for me was to spend no more than 20 min per essay. During the initial few minutes of each essay, I would read through the entire paper and write key points for each paragraph to refer to later when you start answering questions. This way, you have a good idea of what you've read and you won't be so stressed searching through the entire paper as time is running out.
For QR, I can't really give much advice because that was my lowest section on the DAT (19), other than to keep practicing, skip it if you don't know it, and get the easy points out of the way first.
Keep on practicing, maybe 1 practice exam a day! If you've exhausted the BC prac exams, I also recommend DAT Genius. It is also a great resource and more accurately reflected my PAT and QR scores than BC.
Best of luck!! Take a deep breath, keep on chugging, and before you know it, you'll be done!