You still have your indefinite leave to remain if you were away for less than 2 years.
You can re-enter the UK as long as you:
had indefinite leave to remain in the UK when you last left
did not receive financial support from the Home Office to leave the UK
When you travel to the UK, show the stamp, vignette or biometric residence permit that originally gave you permission to settle here.
If it’s in an old passport, carry both your old passport and your new passport when you travel.
If you’ve lost your original stamp, vignette or biometric residence permit
If you do not have your original stamp, vignette or biometric residence permit, you may not be allowed to enter the UK.
You will need to get a replacement biometric residence permit (BRP).