Not that this may help your problems - but I think squats tend to cause more back pain and problems than deadlifts do. The way they compress the spine from the top downwards under heavy load seems more troublesome than strengthening it and stretching it through deadlifts.

First off those Docs should of suggested an MRI because at this point they have no idea of cause. Like said already an MRI would show if there is damage or what have you. For the most part what has been said is accurate. I'd get an MRI, strengthen core muscles around gut, stretch like jakeko mentioned, maybe invest in deep tissue back massages. Point is you need to find the root cause of your back pain and go from there.

Get an MRI, if it doesn't show much more than expected wear and tear for your age, then it's your week muscles causing you pain.
Week glutes -> tight and overcompensating hamstrings -> tilted pelvis -> pain.

I mean if it's simple back muscle pain then you aren't strengthening them. I see this a lot and majority of people with back pain is weak muscles. They don't stretch and strengthen them. No real exercise at all in the mid section area. It's not just the back muscles but also means the abs, hip flexors,, hip abductors and even your glutes can play a role in back pain. That's the real culprit to your question and most don't want to hear it. "Why would I exercise those muscles if they hurt?" Because they're weak, that's why. I've trained people with back pain to learn how to strengthen their muscles to alleviate pain. Unless they have spine issues like slip discs or whatever then nothing will help but proper treatment which may be surgery. If it's just you got a sore back, start working them muscles. Deca really isn't going to do shit other than maybe mask the issue. I dunno but I wouldn't be throwing Deca at it as a solution. Deca cann 100% fuck you if not used properly. I also work out the muscle groups listed above and I have had ZERO back issues over the years.

Pick yourself up a TENS unit, they’re great and pretty inexpensive these days. Drugs aren’t always the way, even long term use of NSAIDS comes with its own set of issues, if you can find a natural alternative, it was mentioned by JakeKO, definitely go that route. Short term relief isn’t worth long term organ damage.

What has your dry icy it said wrong with your back? I’m assuming they’ve diagnosed it as surgery was mentioned?

Deca isn’t going to do shit for your back. We’re getting old, so the best we can do is train hard and deal with it. Research exercises that can bring you a little relief, but there isn’t a miracle cure. At my age, I can tell you it’s going to rain or snow about three days before it does because of my back pain. I’ve learned to press through it, and keep training. I know it sucks, but once the weather changes, I forget about it until the next episode. Stay away from the quick fixes, as they’re not going to work. A lot of people turn to opioids, but you know that isn’t going to end well. Certain types of THC helps it for me, or at least helps me forget about it for the night. When it’s real bad, I lay in bed, on my back, wrap my arms around my knees, and roll backwards. Temporary relief, but it helps.

Anti inflammatories, find a good ortho to properly diagnose, stretching, gravity boots helped me a lot (takes 2-3 min a day), good sports therapist. Deca isn’t your answer.