I took Psychology AS (AQA A spec) and almost instantly regretted it, got an A and have dropped it at A2 (I now study English Lit, History and Gov. and Politics). I believe that Psychology as a discipline is a science, but does Psychology the A-Level subject qualify as a 'science'? Like **** it does. I disliked it for the same reasons you do: it's all content. If you learn the studies by heart, if you learn the theories by heart, you'll get the grade you want. There's absolutely no independent thinking (even the evaluation of each theory can be learnt and memorised, no kidding) - it's all just a mark per piece of knowledge you show.
Sorry you're having a boring time with it though, only thing to do it to learn the content, smash the exam and then drop the subject. I do feel for you though, I was in the exact same position last year.