Hey, I'm currently doing my A2s and i do both psychology and English lit (AQA) and I've nearly finished my EPQ! (Which is psychology centred) I'd say English may be better in conjunction with French and Spanish as they are all languages. However, I also used to have the same problem when it came to writing essays but the main thing is making sure you completely understand the assessment objectives and how they are weighted, if you know what you're being marked on (contextual points, comparisons to other texts, critical opinions/interpretations ect.) Then you will be better able to understand what you need to include in order to secure the most marks possible. Psychology is also very heavily essay based so I recommend you approach that similarly depending on factual info/applications/evaluation required. It depends on what you want you want to study at university really, but English is regarded as a facilitating subject so it is quite respected. Psychology may be seen as slightly 'weaker' but it'll show you're versatile and may count as a science for certain bsc courses.
I enjoy both subjects, English comes quite naturally to me so I don't feel as if I need to work as hard for it as I do for psychology, despite this psychology is what I enjoy more and aim to study in the future. English is quite time consuming in terms of learning quotes, reading core texts, doing background research, making in depth notes and doing wider reading so if you tend to procrastinate I wouldn't recommend it. Psychology is quite content heavy (but i do biology too so it seems like nothing in comparison😭) but it's very interesting imo, if you can memorise things easily you'll be fine. There is also quite a bit of crossover with biology, maths and statistics which some people don't realise, so if you're not a fan of maths like me, you may not enjoy those aspects. The most tedious part of psychology would be remembering the research methods and studies, but otherwise it is brilliant!
Yes I'd say doing an EPQ is wise! It's university style learning so it really prepares you for the future and it looks good on personal statements as some unis really value it! (I received two reduced offers) but I'd say only commit to it if you're very passionate about your chosen topic and have enough time to devote to it. I found it difficult to balance it with my English lit coursework, as the deadlines were around similar times, and keep in mind you may also have languages coursework. It is a lot of independent work though so I'd say only go for it if you're 100% committed. 40+ started an EPQ at my sixth form this September, and by March were due to present and only 20 people carried on.
If you'd like to know anything else specifically I'd be happy to go on aha.