I was amazed when I saw this post & began reading immediately. Glad to hear you're okay; I too think that the hull CAN be repaired. Even so, it’ll be some time before you really trust the repair.
When I bought my TI, I was concerned about the possibility of taking on unusually large quantities of water in some strange and unforeseen situation exactly like what happened to you... or worse. With that in mind, I purchased THREE kayak float bags and clipped them into the hull's interior: one inside the bow, one inside the stern, and one amidships. Each bag can be inflated by mouth or by pump. I keep them ~80% inflated so they can expand in the heat without bursting. And yes, there’s still plenty of room for cargo. With these bags properly installed, I could fill the hull with water, and still remain afloat. Additionally, I always carry a hand-operated bilge pump, and yes, I have used it unexpectedly when out on my sea kayak (which also has multiple float bags).
I know the TI is a tri-hull boat, and it’s unlikely that more than one hull would completely flood at any one time. Moreover, I've read that the amas on the TI each have ~200 lbs of buoyancy. That would be a volume equal to ~25 gallons of water in each (numbers rounded). Nonetheless, I still use the abovementioned float bags. They’re considered standard equipment on any sea kayak.
Check out http://www.nrsweb.com
and search for "flotation". Here's what I use:
NRS Standard Kayak Flotation - Item #42081
Patterned so that a single bag fills the entire stern compartment of a kayak designed without a center pillar. Available in three sizes to fit everything from the smallest rodeo kayak to the largest recreational boat. These Infinity series float bags use a 10-gauge Urethane fabric that won't leak or...
I hope the above info is helpful to you and others. Best wishes on your situation, and good luck getting back on the water.