I know this is easier said than done, but try not to get discouraged. You are simply doing too much. As a working 30-something adult that needs to maintain a home and car, I know that working less is not a option for a lot of us. However, something has to give. If you have a PCAT scheduled, you shouldn't be working full time AND taking a class if you want to get your scores up. I know we all want to get where we're going as quick as we can, but sometimes it isn't in the cards. If working full time is a necessity for you, then skip taking classes for a quarter (or semester, depending on your school). You MUST make time to study.
As far as study materials go, Collins is a good resource. There was a while where his material was not up to date, but when I took my PCAT last week there were many questions on the exam from his Biology tests. You obviously know what the test is like at this point, but I still suggest buying the three Pearson practice exams. There were questions on my exam from the practices and they really give you the best representation of the verbal and reading comp portions of the test. Additionally, the estimated score range I got on the practice exams was spot on to the real thing and helped me focus my studying. Beyond that, don't load up on too many study guides as it can be overwhelming BUT in addition to Collins and Pearson, Kaplan has some good testing strategies that make their massive tome worthwhile (but don't use their Chemistry section...it is WAY too in depth. Collins Chem is perfect.).
You do need to increase that score, but remember that even if you don't get into the upper 80's and 90's that schools look at more than just your PCAT score.
Hope this helps and good luck!
