Hone in the concepts you are continuously missing and try to relate things to each other. Bootcamp does a great job explaining the things you got wrong. Destroyer, not so much but maybe thats just because the way I understand things is different from Dr. Romano's perspective. Nonetheless, to approach the correct answer there are many ways so just find what works best for you. But tying concepts together will definitely help minimize your errors.
You might have timed yourself with Bootcamp an not with Destroyer. If you spend more time on a questions, you are more likely to get it right. lol, however, I know, it is not a luxury you have on the real DAT.
If you're struggling in Chem, I'd suggest Chad's quizzes. I know all of the hype around his videos are there, but if you feel comfortable that you at least mildly understand all of the concepts, then doing the quizzes may help you refine your knowledge to a basic extent.
On the bottom of the Bootcamp tests it shows you what topic each question is from. Tally up how many from each topic you missed. Rewatch those videos from Chad
After my first bootcamp test I found out 3/4 of the questions I missed were from acid/bases. Turns out I hadn't memorized my strong acids/bases and didn't know my ksp equations from memory 😀