Your thread is indeed confusing, veering as it does between Psychology or Law, Gap year or not, one of your current 5 unis or a complete change into 5 different unis.
Overall, you just sound massively confused and I think you need to focus on one question at a time, which needs to start with Psychology or Law? You have said, "I don't really want to do Psychology" and "I really want to do Law with a passion" but yet you are still questioning, "which is better, psychology or Law?"
If you know that you would prefer to be studying Law, you're not risking that much in declining your current offers to do Psychology. The only question is whether you would be better off seeing if you could transfer into Law at Birmingham (for example) before you decline them, or whether you would prefer to see if there is something "better" than Birmingham in Extra. That is why I would suggest doing some phoning around next week.
The Year Off route is a whole other ball game and the only way that realistically you are likely to get into the top top unis like Cambridge or LSE. Judging by the indecisiveness of your posts, however, I think it could be a good idea to try to get something sorted out for 2019 anyway (in Law) so that you have that option in the bag. If you subsequently decide to opt for a Gap Year, you will have had more time to reseach how you could strengthen your application in that year and could withdraw from UCAS at any time with no bad feelings and reapply as a fresh applicant in the next cycle.