My heart goes out to you. I have had two lumbar fusions since 2021, the last one a revision of L4-5, with an extension down to S-1, which helped me a lot. I know I need further surgery, for my neck and pain on my left side of buttocks.
My advice to you, and others who stop the oxycodone so quickly after surgery due to side effects or feeling drugged, is don’t! It is so important for your recovery that you Not be in such terrible pain, and to get some sleep! Sleep is so restorative. Please, take your pain meds, and take Mira lax, or whatever the doctor ordered to keep your bowels healthy.
I agree with coach Dave, this pain you describe sounds like you need a consult with your surgeon.