Hi,
I was attaining As during year 12 when most of my revision consisted of flashcards, and using said psychology booklet that I had been given for each topic - so, as to say, that this isn't a bad revision method. What I found really elevated my knowledge and helped me attain higher marks was the blurting method. This changed the way I revised and I found it particularly worked well for psychology.
Are you doing AQA? If you're using the AQA textbook where is it formatted with AO1 and AO2 on the left-hand side, and AO3 on the right-hand side then I would definitely give this method a go! It does take some getting used to, but is unbelievably worth it. You will need a whiteboard and a whiteboard pen - get an a4-sized whiteboard, as any smaller and you won't get enough information, and any bigger and you'll be putting too much information on there. I would take a double-page spread, so, for instance the MSM, and write MSM in the middle (so whatever the spread is titled) and then write the information I needed to know around it: treat it like a mind map. Use diagrams, whatever works for you. Do this for AO1 and for AO3. Take a picture, put it in a folder on your phone. Rub it out. Do it again from memory. Look at the photo you previously took. Fill in any gaps with a different coloured pen, read it aloud to yourself and explain it. This is such an underrated method. I did this for every topic that I covered at A-Level. It is time-consuming, but if knowledge is what you feel you want to improve, then definitely try this - naturally, it will also help with making links across topics and evaluation, as well as help with essay structure.
EDIT: Biopsychology, in specific, is very knowledge-based so I would focus on learning all the key terms. Issues and debates is a more difficult topic, and tends to pave the way for an argumentative essay. It would be best, to obtain higher marks, to choose a few examples that you're going to learn off by heart for each side of each debate, that you can use in an essay. Don't limit it to this, also learn WHY the use of a particular debate in that topic strengthens it, or may limit it.
Sorry, this is very long. It sounds like your knowledge is quite good as you seem to be doing quite a lot to solidify it, although I would suggest trying the above method. Doing the exam questions is good, that's what I did, and it certainly helped me get familiar with exam phrasing and command words! Maybe the issue is with your technique? The lesson I learnt at A-level is that you can have all the knowledge, but being able to apply that knowledge and USE it effectively is what really gets you the marks, especially in the long-mark questions in Psychology. If you're happy to send me some essays you've written, I can give you some advice on what you could do to improve?