If you want to keep lifting heavy and cut then you can’t sacrifice protein intake. You will need to keep it as high as possible within your calories to hold onto the muscle for lifting, it’s unavoidable.
I did a 10kg weight cut a couple of years ago and I saw good results (strength retention) by upping protein in meals and dropping carbs.
For health you need some fat in your diet too.
I believe the best way to lift heavy on a cut is to get a good hit of carbs an hour or so before a workout to give you energy, and otherwise prioritise protein above everything else.
What do you consider low protein and calories?