I don't want to go to my insurance choice

If you are certain that you don't want to go into Clearing either, there is no point withdrawing from your insurance choice, as far as I am aware. You are not contractually obliged to go even if you meet their conditions, so why not leave your options open?

Ive heard it's more difficult to get out of your insurance though on results day? Yeah I don't want to go into clearing.

The problem arises if you want to go into Clearing and have to wait for your firm/insurance to release you, which can take several days, by which time a lot of the Clearing places will have gone. This isn't an issue for you, as there is no urgency in getting them to release you. I think it's better to be cautious at this stage, in case you change your mind over the summer.