Can my dad withhold insurance info from me because I won’t talk to him?

Unless there is a court order or settlement requiring him to cover you, he is not obligated to provide insurance for you once you turn 18; it is voluntary for him to do so. If it is voluntary, then not only does he not need to do it, but he also doesn't need to provide you any information about the policy--you have to talk to him if that's his "price" for the information. (And if he is providing it voluntarily--why won't you call someone who is providing a valuable, many-thousands-of-dollars-per-year benefit to you? Regardless of your feelings for him, you have to look at it as, "Is the occasional phone call worth $8,000, $10,000, or more per year?" And if the insurance is not worth the occasional contact, then dont' count on him to insure you but get--and pay for--your own insurance.)
If there is a settlement (such as from a divorce) requiring him to provide the insurance, he also has to provide information about it: if he won't, you could sue him for breach of contract (the settlement is a contract) to get the information and force him to honor his obligations. Similarly, if there was some court order or decree, you could bring a motion to hold him in contempt of court for not obeying the court's instructions. A family law attorney could help you do these things.