So, I want to do some martial arts, for self defense. Ideally one that will be useful without giving me CTE, or any long term bad stuff, even though I feel this is already asking for too much 
I don't live in the U๐๐ so gun related stuff isn't really an option.
I'm somewhat heavy, with a year of experience in lifting, and my cardio is not the best, but I can do long walks (of 1 or 2 hours) before getting tired.
I'm going to move to a bigger city in September, and there's a lot of stuff available, so you can comment on the more niche options.
So yeah, any advice from your experiences is welcome lol
If I had known people started arguing over my post I wouldn't have made it.
I'm not saying I endorse the practice, stop acting like the kind of people who do go around picking fights.
While you are correct that even a single punch carries a risk of death - that's why you don't pick fights - it remains a fact that humans have fought each other without death being the intended outcome for literally the entirety of human existence, and that currently in most places the vast majority of humans will never get into a fight where murder is intended.
Because of this, there is a certain etiquette around even self defensive violence that exists in all societies, and the majority almost universally regard pulling a weapon when attacked by an unarmed person to be a socially and legally unacceptable decision, regardless of the actual statistical reality of the risk of death in unarmed combat - unless there's some other mitigating factor like being jumped by a group or being a woman being attacked by a man, at least in theory.
While being thrown in jail for manslaughter is arguably better than being killed, it'd be better for neither to happen - and martial arts allow you to accomplish this.
I note also that you had no response to my assertion of the impractical nature of your advice - this is something police departments have put a lot of effort into analyzing and figuring out, as they're the only demographic of armed individuals who are somewhat regularly in combat with unarmed or melee-armed individuals. They have found that attempting to draw a firearm is useless even within distances as far as 21 feet - and most self defense situations turn violent when the people involved are FAR closer to that, often within or just out of arms reach.
Maybe consider who you're talking to and what kind of perspective they may be coming from. If someone is putting their hands on me, there's probably a 98% chance they're bigger and heavier than me.
As said in another comment, I am a trans woman, I am in precisely the same situation.
That doesn't mean what your were suggesting isn't bad advice to give to others - again, if someone put their hands on you then your firearm is going to be extremely difficult to use effectively. Martial arts are genuinely the more suited tool for the situation, strength/size can be overcome - at least momentarily - with technique even when the gap is large, and all you need is to create enough space to either run, draw your weapon, or both.
It's definitely a lot harder for women, but it still very much can be done and knowing how to do it only makes a firearm more effective by increasing the odds that you will actually be able to use it.
Which is why you train to use your firearm quickly and from inconvenient positions.
Frankly, I just don't agree with the notion that guns are useless within 21 feet. That's cop pseudoscience.
Just because cops are saying it doesn't mean it's not true. There's actual studies on the matter and they've done testing. Drawing a firearm and shooting accurately enough times to consistently disable a human immediately - so at least two shots with handgun calibers - is extremely difficult and cannot be done consistently within that range or closer, and again most self defense starts within or just outside arms reach.
That's a large part of why they themselves teach police basic grappling. Most of them aren't any good at it, but they are still taught it for good reason.
Again, it's a matter of consistency - if you try to draw a firearm when someone has hands on you, they are GOING to attempt to stop or disarm you by grappling you, even if likely in a clumsy untrained way.
Obviously, it's much easier to resist grappling when you yourself know how to grapple. It's a skill, after all.
21 feet might be ideal conditions but if their hands are on you already how the fuck are you getting a gun out and pointing it without surrendering the grapple?
do you have three arms?
better to be judged by 12 than carried by 6 ๐
I go back and forth on whether that's true, personally, but that's because of my particular circumstances.
For one, I'm already depressed as it is and I doubt prison would improve my misery circumstances. For two, I am a trans woman and I've heard all about v-coding and I'd rather die than be subject to that.
Ideally, however, neither. And that's probably what would happen if I responded to an attack by throwing the guy on the ground and running away really fast.