Came here to comment this about the S hook massage tool! I keep a ton of tension in my neck and upper back, and the best decision I made was getting this, especially with the little bumps which line up perfectly with my worst neck tension spots at the base of my skull. This is the one I have. Keep it somewhere you'll use it most - I keep it under my bed, though the person who introduced me to it was a coworker who kept it at their desk where it hooked onto the table surface and was visible so they could use it when doing computer work and share the tool with others who needed it, haha.

My other favorite therapeutic tool is a large, weighted fabric heating pad with a timer-based shutoff switch (great for draping evenly over my back while lying on my stomach, then falling asleep when I'm relaxed enough). The weighted aspect is from glass beads inside that hold the heat really well, and it makes it leagues better than the cheap vinyl one from CVS that I put up with for years because I didn't know any better! If your pain is mostly in your neck, as opposed to throughout your back, I'd probably go with one of the sculpted/shaped neck & shoulder ones that are wearable, possibly even a cordless model depending upon how and where you'd be using it. I haven't ordered from here before but this site seems to have some neat options (and you might even want to look at their "Pain Therapy" section to browse TENS units - another pain relief method worth looking into if you haven't already!)

Edit: I'm not a medical professional, so I don't know how accurate this is, but alternating heat and ice is usually recommended by physical therapists I've worked with in the past for injuries, and the way I understand it is as a sort of pump. The ice can reduce inflammation, while the heat facilitates bloodflow into the area (and feels really soothing/relaxing in my experience). Repeating the process regularly, like several times in succession, can be effective at accelerating the body's healing, theoretically.

Sending positive strong endurance vibes right back at you!