If you're eating at a deficit, and tired of lifting heavy, why not cut the lifting down to 2 days a week? Squat/OHP one day and Squat/Bench the other. Use the rest of the time to do cardio. I'm a noob and wouldn't know what to suggest for sets/reps.
I don't know, but seems like if you are sick of lifting heavy, take a break and focus on other things.
"Ignore the pain." - Vince Urbank