If the branches are as brittle as you say, that's not good. See what the nursery has to say. I'm sure others here will have some advice for you too.

My guess is that it is severely root bound and needs to have the roots soaked. Also, it was probably grown in a greenhouse and used to high humidity. You will get a better answer on the houseplant forum, we talk about the edible fig here.

TOO MUCH WATER This is almost alway a problem for us northerners because our trees must be able to take a few days with out watering on our hottest days. Here is what I do that works wonders and makes it possible to leave my tree alone for 4 days in upper 90F weather in the summer.Both tangerine trees are 49 weeks old from seed sprout. I use a shop vac plug into GFI now to protect from water that might drip from pot. My trees are also now permanently place on the vacuum chamber bucket for the cold season 'no setting up necessary". 10 seconds morning 10 seconds evening brings me close to my tree 2 times daily to catch problem while they are small. \vacuum chamber hold pot off cold floor. I mulch the surface to hold down evaporative cooling. A fan will do a fantastic amount to draw moisture from the leaves. This will draw much more on the water in the soil. Works best with leaves on the tree before they drop. Don't change your soil now but wait till spring and use what I am using to get you through the winter.

Had the tree for about 3 or 4 years. I had it in the ground for 2 years, and it wasn't growing or doing anything. Repotted it into this pot and it started growing nice. Only one fruit last year though. It's a dwarf tree, and doesn't seem to grow much taller. Not sure about your comment about massive flush of growth, I don't see any new growth and I see some dying growth rather. I feel like it's all of a sudden gotten unhealthy. Not sure if it has anything to do with all the blossoms, there's so many of them....