*URGENT* Swim team anxiety + coping (plus a long ramble woohoo)

Summary- I have swim team for the first time this year tomorrow and I'm really not looking forward to it on the grounds of being uncomfortable with gender stuff.
I'm pretty sure no one will see this in time for early tomorrow morning.. Grr.. Oh well..
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I guess since I've finally broken away from clinging to the idea of being cis and/or not caring about my gender at all, I've just been slowly suctioned towards the idea of being a guy. And it's great that I've finally reached an identity that makes me feel comfortable.. On the flip side, it's like magnetic attraction. The further away I kept myself from my own thoughts, and feelings of discomfort around being female, the easier it was.. The less real.. But I guess the closer I got to being true to how I feel and how things are for me (at least right now).. It became more difficult to resist the pull.
I almost wonder if I should be more hesitant to acknowledge this part of myself, more ashamed, more in denial, but apart from the nasty comments I see on social media sites, and my mom cherry-picking apart my explanations of my experience thus far, and everyone who genders me as a girl without even thinking about it, there's nothing and no one in my life telling me off. No one to say "no, you're a girl, and you have to live with that".
Now it seems that the magnets are pretty well stuck together, and I don't think I could pry them apart if I wanted to. The ideas of "who I am", and "boy", have sort of adhered to each other.
That scares me a lot. And now I look at pictures of myself from even just a while ago before I cut my hair, and feel an odd sort of disconnect from that other person.
Sometimes I feel like I'm floating and that things still don't make sense, but what brings me back is that.. Rush. The rush of excitement I know I've felt every time I push away an obstacle in between the magnets. Imagining myself in a relationship with someone /as a guy/, gives me that rush. Looking flat chested gives me that rush. Hell, just thinking about having beard stubble and a deeper voice gives me that rush.
I don't know.
Anyway.
Now that I'm more solid in my feelings, the blows just throw me more off center and make me more unhappy.
I do not want to use the girl's locker room tomorrow.
I do not want to wear a girl's swimsuit tomorrow. (Luckily I've found an 80% remedy to that issue last weekend by layering a sports bra, then a one piece, then a "girl's" rash guard and swim shorts.. But in a way it's still not quite enough).
I do not even want to be seen as a girl tomorrow.
But it's inevitable and I hate it.
And I have nobody to tell me- "It's okay, you're valid, you're a boy, you're whoever you feel you are and this doesn't change that". Nobody to counter all of the "girl" and "young lady" and "daughter"s. It feels dumb to try and ask someone to do that. Especially because something terrible in my mind still tells me that none of it's true, and that nobody does or ever will see me as male.
I've had some anxiety issues since Fall, and that is really not helping things..

Any advice on how to cope?

 

"In the water, I'm just a fish" has sort of become my mantra for when I'm feeling stressed at the pool. You were all definitely with me in spirit, even when I felt really alone. I've powered through. I know I can't just click the pause button and fix everything that's wrong with how I am right now.. I've gotta move forward! And Tony's theme is indeed a really fun song. I listened to it before swim team yesterday and it cheered me up a lot.
My first two days have gone pretty well.. I feel somewhere from a little nervous to very anxious for a lot of the time, (especially in the girl's locker room eesh. It feels like everyone's staring at me.. And like I'm not supposed to be in there) and both emotionally and physically drained afterwards.. But I'm really enjoying the swimming itself, which is something I love to do, and getting so much excersize on a daily basis is good for me, I think. I'd forgotten the wonders it does for my mood and self esteem.
Thank you guys for your replies and encouragement.. They made the whole experience much easier on me. :')

 

Haha! Well, I try my best..