Honestly, getting even 75% across the board is a considerably achievement and not that easy. As above unless you've been consistently reaching that but had one term blip where you got minimal passes, it's probably not realistic.
You may need to manage your expectations here and focus on a more realistic goal of a 2:1. Fortunately in general graduate schemes don't particularly seem to care if you got a 1st or a 2:1 and just want you to have a 2:1 to tick that box and then focus on other aspects of your application. So getting a 2:1 isn't really going to be any great barrier.
Aiming for a 2:1 also gives you more leeway to ensure you don't burnout, and also more time to start putting together your CV, identifying roles to apply to and preparing a good application for them, and maybe picking up a few activities that might be useful in that realm in terms of developing transferable skills or having a bit more work experience (although, hopefully you have done an internship already or you may find it challenging regardless of what classification you get).