Advice for tropical hibiscus would be much appreciated!

[Fatalliecat]

Is my hibiscus tree too far gone? It’s a special tree that I got when my dog passed away so I’d like to save it if possible. I’ve had it for 3 years but haven’t seen any flowers the last 2 years. I bring it in every winter, but always manage to get spider mites, regardless if I treat it. I pick all of the leaves off that are affected and cut back the branches every winter. I’ve used miticide, neem oil, and soap water (not all at once) to treat the mites. I live in southern Tennessee where it’s humid during the spring and summer months. I replanted it in a larger pot last year.
I haven’t seen any new growth on the branches this year, even though a few weeks ago when I slightly pruned it, the branches were still green. I just noticed that the bark was beginning to peel. I pulled back a piece of bark and it looks like the tree is rotting! There are wood mites under the bark as well. It does look like it affected the whole tree. However, there is new growth at the base of the tree! Is there any hope? I sprayed it with fungicide to start. Would the tree grow back if I cut it down to the base?

 

[Catalog of Plants]

the affected area must be completely removed. If there is new growth underneath, it will most likely survive.
Usually they rot from a fungus, perhaps when they were replanted in the ground with chicken manure in the form of fertilizer, raw or not properly processed.
Do not buy such soil with fertilizer for potted plants.
Sprinkle wood ash on the ground around the plant; now replanting it is risky only if you get help from some nursery where they have experience in replanting, since you still need to look at what’s wrong with the roots in this case.