Hi Holly
I'm sorry to hear that it has all been so stressful for you. My advice would be to think about the end point, ie if the end point is that you want to have studied for your degree at Durham, then make sure each small step you take takes you down that path.
If you decide to proceed this year, try to bear in mind that most people seem to end up loving the college in which they are placed and equally most seem to find advantages in terms of in-built friendship about sharing a room. I know several people who thought they wanted self catering who found the catered option to be helpful in being a time saver (no need to be shopping for groceries / prepping / washing up). The thought may be worse than the reality, but in the end only you can decide if you are willing to give it a go. If not, you have the choice to ask if you can defer (may or may not be agreed) or withdraw and go through UCAS again with results in hand.
If you defer to 2024, there would be no guarantee that the accommodation allocation would be any different next year because there is an element of random allocation about it. If you would be happy to take your chances and be happy (resigned) if the allocation was no better next year, then that could be an OK decision for you, provided you have / can find something to do this year as otherwise you might feel that you are marking time until September 2024.
You have a lot of changes going on in your life and that is difficult for anyone, but you have done well do have got through your A Levels and be an offer holder for course you want to do at Durham; you should be proud of yourself.
Good luck!