If you don’t want to enroll in any paid course;
To cut the noise, buy the official guide and get it done. It is the only central workbook that will help you with the syllabus coverage in the stipulated time.
Plus from your score, it seems you just blindly jumped in to give the mock exam. For example, DI you couldn’t address a single question. Verbal you did according to your target score, Quant you need a jump.
Start with the Quant syllabus from the official guide and practice some questions here on GMAT Club. and follow with Verbal. For DI you need to understand the structure of the questions from the official guide, you’ll be there.
If you feel you’re lacking confidence, get enrolled yourself to any paid course. Just book any paid course. Follow routine.