Martian - is your tri in a pool or open water? Going to the pool 3x a week is a great plan! But if the tri is open water then until you know what chop feels like you don't really know where your skills need to evolve to. Also the open water is a challenge that you just have to go out and do. Basically survive it once and then you know for certain you can finish and not drown and from there its easy.

Also, be certain that the lifeguard has seen much much worse!