It’s really up to you and what you want to do. With psychology there are the maths elements, are you good at maths? Figure out your weaknesses and strengths. (Although with maths it’s mostly statistics or simple math so do not stress yourself too much on that area)
With sociology its more humanity so are you good at stuff like History and R.E. Prepare for a lot of reading! Another factor to consider is what job you want to do- with psychology you can do a wide range of things such as being a psychologist, therapist or something of that sort but it doesn’t always to be that way, you can also get into business and marketing with psychology do not always think psychology is a one way route to medical/neuroscience! So many options.
With sociology you’re also aware of law so you can get into something with law(?) and also marketing, journalism, social work or teaching and public relations.
Do what you love.