I’d be concerned about you doing geography without the GCSE. Although psychology is offered at GCSE, it’s a rare subject and the teachers at A level work on the assumption that no one has done it before. The same won’t be the case for Geography and you may end up being all at sea if you’re not able to follow the classes. I had to do a module at uni where the lecturer assumed that everyone had A level biology (we didn’t) and ended up only effectively teaching about 6/45 people. He did not slow down or change his material because teachers generally just don’t. He recycled the same materials for us (allied health professional students from diverse educational backgrounds) as he used for medics, dentists and physiology students. It was a pain in the neck and as the exam was multiple choice we ended up just ignoring his material because it was impenetrable.
I would advise extreme caution with geography. You’re not setting yourself up for an easy two years.