Assuming every day the same donations pour in, it'll take about 4,227 days:
355,000,000/84,000 = 4,226.19047619
That many days divided by 365 means about 11.5 years to reach that goal.
4,226.19047619/365 = 11.5786040444
77 + 11 =88, so he'll probably be 89 before he's out of debt, assuming no other financial penalties from lawsuits happen. Or he could declare bankruptcy...