Technically these are 3 separate incidents and would constitute 3 different claims. The driver that hit you most recently would be responsible for the damage that he caused, but you would be responsible for the damage from the other incidents since there is no one else to hold responsible. Unfortunately that means you'd likely have to pay 2 deductibles before your insurance company would cover the remaining damage. I would recommend filing the most recent claim with the driver that hit you and disclose the previous damage. Once those repairs are done then you should contact your current provider and proceed forward with the remaining damage. As for being dropped by your current company, unfortunately they will be the ones determining whether or not they will continue to insure you. Each company has their own underwriting standards so it's impossible to say with any certainty. But if you do find yourself being non-renewed, you should shop around
with as many companies as possible to find your best option.