There are also financial implications to leaving during a year, rather than after it finishes.
If you leave during the year, your Student Finance will stop. You will be expected to repay second year Maintenance Loans/Grants for the year, immediately. If you're locked into a tenancy agreement, you have the double whammy of then having no income with which to pay your rent to the end of the contract.
If you leave after the end of the academic year, you will revert to the standard repayment terms, where you pay in small instalments after you reach the £21,000 threshold. Also, you won't have to return any grant element.
Unless your parents' support extends to a significant financial contribution, you might want to try and postpone your job until after the exam period, and limp through the rest of your coursework/exams as best you can.
After this, you won't have enough SF entitlement to start a new degree from scratch in future. It might be best to wring as much out of this attempt as you can if you're being offered the Diploma. If you can postpone the job start, it might make continuing at uni for a few more months, a bit more bearable.