I am sorry to hear that.
I started up TI swimming as a means to recover after an accident. Among other things i broke my neck. I was dizzy for a long period of time though all the head down positions in the water felt really good. Using the the water to help support the weight of my head. I stayed in the shallow end and just practiced skate, superman flutter and fish. I could practice small movements in skate, such as putting a 9o degree flexion in the elbow to initiate the catch. This way i could make small improvements without having to deal with co ordinating side to side movements.
I am afraid i can not offer advice specifically to your case. But what i would say is that any time in the water would help. I only started swimming after the accident and the benefits have been amazing. Not only as a physical outlet but a form of meditation. I would say starting TI would be a great option. Its great to have a goal and a sense of purpose after these events. TI swimming could be the way forward.