My golden completely loses it at the vet - any tips?

i have a 4 year old golden retriever named Biscuit and he is genuinely the most chill, friendly dog in every single situation except the vet. at the vet he transforms into a completely different animal. shaking, drooling, trying to climb onto my lap (he's 74 pounds), whimpering the whole time. the tech literally had to close the door because he was howling loud enough that other patients could hear.

the wild thing is nothing bad has ever happened to him there. no traumatic procedures. he's had routine checkups and vaccines and that's basically it. our vet is nice and patient. but something about that smell or environment just short-circuits his brain completely.

we have an appointment coming up next month and i'm already dreading it. he needs heartworm bloodwork and updated vaccines and honestly the anxiety it causes both of us just makes me want to cancel and pretend the whole thing isnt happening. i know thats not the answer but also... ugh.

has anyone dealt with this and actually found something that helped? would love to hear what worked for other goldens especially