Yes, that sounds like typical MS to me. I can egt all kinds of feelings that come & go in different parts of my body - burning, tingling, numbness… I’m on Gabapentin which generally works for me. I’m glad the Amitriptyline has been better, but if he’s not happy with it another one to try is Pregabalin, which is meant to be very good.
Something else I’ve been doing recently is mindfulness meditation, which is known to be beneficial for pain management & things like anxiety & depression. Mindfulness is simply about noticing what you’re experiencing in the moment - what the different bits of your body are feeling, what your breathing is like, what you can hear or taste, what thoughts & feelings you’re having. Often we’re rarely in the present moment - we’re worrying about the future, or feeling things based on the past, instead of just being aware of what’s going on right now. And when we are aware, we’re wanting to change what we’re experiencing. But with mindfulness, you simpy notice what you’re feeling & let go of the desire to change it. It can be tricky to do, especially with something like the pain - the idea of just noticing it but not doing anythng about it sounded like torture to me at first. But oddly, I’ve found it really helps. I used to say I’m in pain, but actually that’s not true - only a very small part of me would be in pain, and even then the pain would come & go, The rest of my body will be feelng all kinds of other things. If you want I can send you a link for a website that’s got a simple introduction to it.
Other than that, I just want to say welcome to the board (to your partner as well). There’s a wealth of knowledge & experience on here, so don’t feel bad about asking a many questions as you need.