A level Criminology vs Psychology

I know it’s not an A level; which is part of the problem. I quite like the idea of going into some sort of career to do with criminology such as working in the counter terror field, although it’s only one out of many career options at this point, I don’t really know what the level 3 diploma in criminology is about and if it would really be something I’m interested in. Also as it’s not an A level will that effect my chances of getting into university? Would psychology be any better of a choice?

I’m already set on doing A level English Language and Literature as well as A level Graphics. I’m just still cloudy on my other choices; I want to do 4 A levels as I’m very indecisive and want as many options as possible. I just want an insight from anyone who is/has taken A level Criminology or Psychology to tell me how they found the course and what they studied. Thank you.