Firstly, your best option is to go back to the school where you completed your PPL training. The only issue might be the time since you took the PPL written exams. You will only need to complete those items not completed and pass the PPL Skill Test but to do so your written exams need to be within the validity period.
There is no longer a 4 April deadline for the IMC, it has been extended for a further 5 years.