Help with a very weird situation I’m in

Okay, so to preface this. I just turned 18 (may 7th), and I just got a job offer at a local private ambulance company as an EMT, and I’m set to go for orientation the 17th of this month. I also, a while ago crashed my car, and my step dad is allowing me to use his pickup. This is all important.

So, just last night I bought plane tickets for a trip to go see my best friend and my girlfriend who live in a a different state. And my step dad is very firm in saying I’m not allowed to go, even though the tickets aren’t refundable.

He’s saying that I’m “jeopardizing everything I’ve worked so hard to accomplish” even though the trip is scheduled to end well before the time of my orientation for my EMT job (plane lands the 15th) and I’d only miss 2 days of my current job. He also said that if I go he will only allow me to use the pickup truck for one more week before he stops allowing me to use it. Which is completely fair since it’s just truck, but idk. He’s insisting that I’m making the wrong choice.

And then he sits me down and tells me how these relationships I have with my girlfriend and best friend are fake and “fantasy” because it’s physically impossible for people to bond online, and that even though my girlfriend and I have been dating for a year, and my best friend and I have been friends for 4 years. It’s all just fantasy and not real. And he openly mocks and makes fun of me for wanting to date her. Even going so far as to say he guarantees she’s cheated on me multiple times despite never even so much as speaking to her once. He just openly makes digs at both me and her.

I know he doesn’t like me, he’s never liked me. So I’m pretty sure this just another way to punish me for something. But I don’t know what to do, am I in the wrong? I just need some advice