As someone who also generally leans towards science subjects and took A-Level Psych for a while, I wouldn't recommend it if you're not too fond of essays. I agree that lots of the topics were really interesting, but if you have a scientific mindset, having to evaluate and write 'subjectively' about research and theories kinda kills it. It also doesn't help that psychology is a relatively new field, and the most reliable and direct methods of investigating the brain (i.e. neuroimaging) are still pretty basic, so lots of information that you'll be taught is glaringly open-ended and inconclusive (although, in itself, I can see how that's appealing).
Also, 16 markers in psychology are the worst kind of essay because you pretty much just use the same technique and structure all the time - its almost like a fill-in-the-blanks for the different topics (think GCSE Religious Studies 12 markers).
Bear in mind that, even if you don't take A-Level, you could still pursue an interest in psychology later at uni.