It all depends on what you are trying to achieve. Assuming you took the sensible route and already have an IR, you technically only need to take the CPL exams.
My biggest question is how/why on earth did you get an FI rating (requiring 150 hours PIC) but not a CPL (requiring only 100) ??
Try to book an exam online and see if your old school sign-off is still active. If it is then bite the bullet and book the exams. Otherwise maybe contact them and ask them to reinstate it.
You have at least 2 weeks until your exams expire, how come you can't fly one flight?