Yeah...the "insurance" in ED isn't like rl insurance where you pay premiums and then a deductible when a claim is made.
In game, the premiums either don't exist or are paid through some mechanism we don't know about and you just pay the 5% deductible in the event of a ship destruction. Try to never leave a star-port without having at least enough money to cover the insurance for whatever ship you are flying at the time.