Spinal Erector Imbalance

Hi I’m new to the forums but I’ve been training for about a year. I’m 5’10 170lbs and I guess about 15% bodyfat. I’m about to start training more seriously and go an a mass gaining phase but seem to have a imbalance in my lower back which i want to address first.

My problem is that my left spinal erector feels much bigger than my right. I’ve had minor problems with my lower back before due to deadlifting with poor form. But while I have improved my deadlift form I’m worried that this imbalance could lead to injuries in the future.

Anyway I how would I go about correcting the size (and most probably strength) difference between the two sides? Are there any exercises that emphasize or isolate one erector more than the other?
Also should I stop deadlifting until this is sorted as it may be working the strong side more than the weak and making the problem worse.

Thanks in advance

Do you sit on your wallet?

Or, if you are a woman or the leg-crossing type, do you always cross your legs a certain way?