What's helping you overcome your fear?

Distraction.

I have an asburd amount of hobbies and projects, some of them very big.

As a famous actor once said, "I ain't got time to bleed."

Fear is real, I experienced it pre-op too. For me it was fleeting, but severe. I didn't have it all day, every day, but I'd get it now and then and it hit hard. I'm always able to pull myself out of the abyss by just having a "come to Jesus talk" with myself about the realities and my control over them (i.e., very little). While I am a person of faith, I didn't lean on that as much as I did logic. Keeping busy helps a lot, I buried myself in work and it's when there were down times when I would have issues.

Your hospital will almost certainly have a social worker who can help you work through your anxiety. I did a few sessions when I felt mine was getting out of control and she gave me some things to think about that did help.

The Dune quote is a little odd to me. I don't think you can train yourself to "not fear". You can train yourself to face fear, I've found the more you face it, the less it effects your daily life.

I'm more of a "Book of Five Rings" type.

"The warrior must train day and night to make his mind free and unhindered. Perception must be strong, and you must accept that in combat, death is always a possibility." - Miyamoto Musashi

Here, the author suggests that facing fear involves accepting mortality and training to act without hesitation—a practical approach to overcoming it.

I've done a lot of things average folks would be afraid to do. I was always afraid, you just face it and do your job. Every time you do this, faith in your ability to do so grows a little stronger till the fear no longer has much effect.

As @survivor5280 suggests, in this fight, the fear is uncertainty. When the mind gets quiet the "what ifs" creep in. I've found the same formula worked for me. I answer the what ifs in my mind and steel against them as best as I can, then they effect me less. Sort of a "whatever happens, happens. I'll do everything I can but it's not in my control." If it gets to the point where you need help with that, get it.

Secondly, I find that keeping busy in mind and body helps a great deal. Excercise, learn something new, read fiction or non fiction.

That's just my opinion, I could be wrong - Dennis Miller

Jay, fear/anxiety is our natural human response to the unknown. You would be abnormal if you planned to tap dance into the OR and belt out show tunes.😉
I like your Dune quote and if it helps, it’s your mantra. Best,
Phil