@Christina985 If you spend some time reading on these forums, you would know not to fall for Airbnb's "million dollar guarantee." Definitely have your private insurance, but maybe shop around to see if you can find a better deal than what your current company is quoting. Do some searches on this site, for what other hosts have recommended.
Personally, I don't have private insurance, but that's because I just host a private room in my home for 1 guest, so I don't experience damages and no one can host a wild party, and don't live in the US where everyone is so sue-happy. There's little here a guest could wreck that would be expensive to fix or replace.