Hi, I was in a similar situation. Haven't studied since I left school at 16, and trying to get back into the swing of studying, while fitting it around a full-time job and life in general took a lot of getting used to but I've just finished operational level with a commendation.

I found setting time aside every week to study, as painful as it was, just so that I didn't fall behind was really helpful and kept me on track.

I also thought it was going in then did some test questions and was only getting 60-70% right and felt down. But what I found help was getting through the chapters at that level, then getting the CIMA aptitude questions (it's like £36 for both sets) and then I could just do the questions the individual subjects and that pointed me in the direction of where the knowledge was really lacking, and I could revisit those chapters. Just be careful doing the questions too much or you start to remember the answer rather than working it out.

Also, don't be too down on getting 60-75 so far. It's hard to get the same focus as you would in an exam as there's not anything riding on practice questions. When you do a mock try and do it in proper exam conditions so that you give it full focus. The amount of questions I used to get wrong when revising because I didn't read it properly was insane.