want to move abroad asap but dont know how/where to start

Start with the basics. Do you have a passport.
From there, do you have a source of money sufficient to pay for the travel, and to support your life there?
What about visas, if you're intending to stay longer than visa free travel would allow?
It seems that the key to this would be your art taking off sufficiently that you're making a living from it.
I'm reading Shaun Greenhalgh's book now, A Forger's Tale. It's a great read and has some interesting things to say about the greed and lack of integrity within the Art World.
If you have someone willing to buy your art for a price you're willing to accept, that's a great place to be. Get on with creating your art. It's a win win win. You enjoy the process of creating art, you get paid for it, and your clients get a piece of art that they want.
In 2026, what you eat and drink can be as good or as junky as you want, wherever you live in the world. Don't blame the UK if you're eating fake food that's devoid of nutrients. Blame yourself. And take effective action to fix it if that's the case.
There's multiple possible reasons why your bruises are slow to heal. This may be a canary in the coalmine. The early warning sign that something's not right. Going to town on your nutrition and seeing your GP about this, with you pushing for blood tests would be a sensible response to your slow healing bruises.
Eckhart Tolle's The Power of Now is a great book. Whenever you start focusing too much on the past or the present, remind yourself that you're living in a series of nows. And the more you live in the present moment and focus on the now, the more you're likely to have a great life.
You could knock up some Gannt Chart project plan for your move abroad.
Or you could plan it less formally.
The main thing is to take appropriate action to make it happen.
When you come to doing it, it's one step at a time. Focus on each step as you do it and get it done. Then move on to the next step. Don't be perfectionist about each step. Just do each step "well enough".
There's also the philosophy around "rejection". Aim to make it so that you don't live in a state of "rejection". "Rejection" in this context being where you don't accept things as they really are. Where you're wishing that the current reality was different. EG "I wish I wasn't living in the UK". "I wish moving abroad didn't feel so overwhelming".
It's better to accept whatever reality you are living in. EG "I accept I'm living in the UK and I accept that I feel overwhelmed at the prospect of moving abroad."
Combine acceptance with you taking effective action (more often than the average person) and you'll have a great combination.
You're a great person. You deserve a great life.

idk how to come up with a proper plan/and how can i take my dog with me, where to go. it feels too overwhelming. but i DO know that's what i truly want, and what will finally make my life feel complete, i need to be like, somewhere else. maybe spain, or thailand, anywhre but here tbh. there NO sun, it always rains, my bruises dont heal at all bc the food is so fake and void of any nutrients, i just feel so restless, i haven’t slept properly in weeks, other than the odd few hoursandwhen I do manage to sleep, i wake up in the middle of a panic attack with chest pain, i have constant nightmares, mix of my own past and the stuff from the files, wish id never read them i feel sick whenever i remember the worst parts. i just want a fresh start...

Honestly i can only offer some advice.
Before you move you need to come up with a plan. Going without a plan will leave you with no money and no place to go. Think about the places you can go , can you speak the language, find work there? Think of the essential things. I'd say when you find a place to go, scope it out. Take a week out of work or whatever you need to do, leave your dog with someone you trust. When you find the country you want , look for a place to stay that will allow your dog and a somewhere to work. Please dont just jump into whatever without a plan. When you know how much everything is, start to save. Depending on how much you earn or have, start the moving process. Pick up more work or anything to get money. Save every little and big thing you can, give yourself a suitable deadline and move.

yh i'm trying to put a plan together,but im such a coward i keep panicking about it and i don’t trust myself to get it right. the problem is i cant really have a trial week, if i go somewhere and then come back i can probably say goodbye to my passport, lol, nobody accepts that i wanna move abroad, so i cant even get irl advice. but yeah i'll figure something out!

The best thing you can do is remember why you're trying to start a new life.
If you ever panic just ask yourself if staying in the situation you are in worth the rest of your life. It's also good if you have an outlet, for example journaling your nightmares and panic attacks.
If you can't do a trial week then just search up online places to stay. You dont always have to figure out a for sure place, maybe just stay in a hotel that is dog friendly, then you dont have to come back for you dog/lose your passport and you can figure out your next step. Take your time, the most important thing is money though, you need something to sit on while you try to stand
You need to have faith in yourself, you can do it, you can move and start fresh, you can live a happy life with anybody or anyone. You can do it!!!!

yeah, thats true.. change is scary but i feel like there’s nothing here for me anymore, so sick of just watching the days blur into each other until i can barely tell whats real and what isnt caus it all feels the same

idk how to come up with a proper plan/and how can i take my dog with me, where to go. it feels too overwhelming. but i DO know that's what i truly want, and what will finally make my life feel complete, i need to be like, somewhere else. maybe spain, or thailand, anywhre but here tbh. there NO sun, it always rains, my bruises dont heal at all bc the food is so fake and void of any nutrients, i just feel so restless, i haven’t slept properly in weeks, other than the odd few hoursandwhen I do manage to sleep, i wake up in the middle of a panic attack with chest pain, i have constant nightmares, mix of my own past and the stuff from the files, wish id never read them i feel sick whenever i remember the worst parts. i just want a fresh start...

What country do you want to move to?
Decide that first. If it is somewhere that speaks a different language, then it may be worth starting to learn the language too.

somewhere sunny, relatively lgbt+ friendly.. im thinking spain or thailand seem a good match, a lot of people speak english there too