Hi, I wouldn't say I'm an expert on this but I also do a-level psychology and eng lit (i'm in year 13), I know that you can study psychology in many unis since they require at least one science/ math subject and most of them count psychology in that as well. this could also be a good option as its quite similar to psychiatry- maybe if you go down the psychology root then there might be an option to branch out into the psychiatry field later on. Also I know you can do journalism, eng lit and law because you study eng lit. idk about computing tho because many universities, if not all require you to study a-level math as well if you want to go down that field. Also its worth mentioning that you JUST started sixth form, shouldn't your school give you the option to switch your subjects if you're not happy with them? No pressure ofc, but maybe if you have a passion for something then pick subjects that are similar to that topic. + I know some sixth forms give students the ability to re-sit a GCSE if they need it for a specific course, might be worth asking your head of year or form tutor for that. Hope this helps!