Weak multifidus

Hello there, I'm currently 19 years old and have been having very bad back pain for almost two years. Back during my senior wrestling season I through my hips/back out of alignment. My lower back hurt but not to an unbearable level. Every time I visited the chiropractor, I would get readjusted but then soon after come back out of alignment. The chiropractor told me to strengthen myself in the correct alignment. Doing straight leg dead lifts, I bulged my L5 S1 disc. This was about a year and a half ago. I went through PT for it but the pain never got better. Then after 6 months I went back to a different chiropractor and deep tissue massage person. They told me by that time that the disc was better (which an MRI proved) and to begin working out again. The pain got better to a degree but I still hurt a lot at times. Then I figured out that the last bit of pain was due to lumbar instability. That my inner muscles, pelivc floor, tva, and multifidus, needed to be worked out to fix the pain. They said that my right multifidus was weaker than the left. Anyway, I started on pt for that almost 4 months ago and there has been no relief in pain. In fact, it feels like it hurts now more than right before I started pt. I've visited more than one place and each person gives me stability workouts that don't work. I feel like why they haven't been working is because until recently, I didn't know that you're supposed to feel it in your lower abs when doing the workouts. I try very hard to focus on pulling in the stomach and focusing on the lower abs but it's like they won't activate. I've tried every workout I can find but every core workout i do, the upper/middle abs seem to take over. It's like the lower part won't even fire off. I don't know what to do and I'm sick of being in this bad of pain, especially at night times.