If the planets line up correctly, you can do it in way less, like 4 or 5 months. I'd need to get some orbital calculations out for the whole thing

But simplest case, you lower your perihel to Venus orbit, that'll take you less than half a year. With a perfect gravity assist you can then head straight for the sun at more than orbital speed, accelerating as you go. Free fall time is a fraction of orbit time, and you're going in with a high initial velocity, so a month or two more, max. That's 6-9 months total, but it'll be faster with more Δv