Sorry to hear about your back. I've struggled with this issue for a long time now. Hopefully this information will give you some insight. I started to experience pain in my SI joints about 5 years ago. The pain started out of the blue and at first I thought that it was low back pain. After struggling for months not telling anyone, I finally went to the DR and they dx it as SI problems. Generally speaking pain associated with the SI joint is because of inflammation. It isn't an alignment issue usually, as you mentioned in your post. The first treatment I went threw was low dose anti-inflammatory treatment such as, Motrin, Naproxen, Celebrex, and another stronger anti-inflammatory but the name escapes me. I took these NSAID's (non-steroidal-anti-inflammatory) for months without seeing improvement. The pain was progressively getting worse and the majority of my pain would come at night. Especially laying on my side and coming to the seated position. ( Not sure when you experience your pain) After this treatment showed no promise I went to an Anesthesiologist that ran a pain clinic. He treated me several times with epidural steroid injections (ESI inj) This treatment helped short term but not long term and the procedure is pretty difficult to accomplish since the DR is trying to stick a 6 inch needle in between your SI joint. Usually this is achieved with radiology equipment to verify that needle is actually where it needs to be. Anyway, that sucked and I wouldn't recommend it if it ever comes up. After all the Dr's were dumb founded by me they drowned me in narcs and tossed me to the side and I was left to fend for myself. I tried yoga, stretching, heat, cold, spinal adjustments, hip adjustments, nothing worked. I got a membership to a pool and started swimming everyday instead of lifting. My pain significantly improved and I attribute this to the release of pressure from gravity no pushing down on the joint's all day. After a month of swimming everyday my pain was pretty much completely gone. After a few months I had forgotten about my debilitating pain and thought I had cured myself. It came back though and at this point I was ready to throw in the towel and say fk it and we won't go into what was going through my mind. I had an MRI done and it reveled 3 herniated disks. Herniated disks as you probably know can impinge nerves in the spine which cause pain. One of the sure signs of a herniated disk impinging a nerve is if you bend down and touch your toes you would feel whats described as an electrical current radiating down your legs to the balls of your feet. I never had this symptom so I wasn't to concerned about treating the disks. I had an evaluation with a Nero-surgeon and he agreed that I not have surgery since I am so young (28). At this point we started testing my blood for wired disorders which we found. I have a genetic disorder that causes severe inflammation in my back and SI joints. I was put on Humira which is a TNF (tumor-necrosis-factor) suppressant and since being put on this fking horrible medicine which has to be given to you by a Rheumetologist, I have been pain free for about two years now. So my advice to you is:
1. Stop lifting
2. Start swimming
3. Try low dose NSAID's
4. Avoid adjustments cause if you are inflamed its going to make it worse
5. If you're under mental stress try to relieve that if possible
Sorry it was long, hope you feel better brother.