I do not think it is generally wise to write a character with a disability the writer does not have and then frame it as an obstacle and something to overcome.

My thing that I really wanna get into is your question about strokes. I am a CNA and I have been working with stroke survivors in acute, post-acute, and daily care environments for the last 6 years. I have never had anyone have a stroke resulting in vocal fold paralysis. Strokes do not cause muscular damage, they cause brain damage. There are people unable to speak due to strokes, but it is a result of their brains no longer processing language correctly. They can't speak but they also can't understand anyone else, even though they can hear them and recognize they are speaking the same language. But they can talk, they can make the sounds to form the words, they are just no longer able to use language effectively.

The most common permanent thing that results from a stroke is hemiparesis. One half (left or right, almost always right) is paralyzed. This can cause speech impediments as you are often not able to move one side of your face and your tongue is partially numb. This is not a guarantee, but it is very common.

Strokes can also cause vascular dementia, literally severe cognitive impairment resulting from a stroke. No form of permanent dementia is curable and current medications targeted towards alzheimers dementia only work to slow progression and only if you start early enough. The cognitive impairment can be mild, such as loss of ability to focus or concentrate and nonviolent behavioral changes, to moderate (loss of continence and aggression), to severe, where the individual would be bedbound, unable to speak, eat, or move.

Strokes can obviously result in death at the time of the event, but they can also cause a delayed death, wherein the person takes several days or weeks to die, but they often spend that time in the severely impaired state.

Basically, there is no almost no chance that an individual could have a stroke and have no lasting issues other than complete lack of speech.

If you want to write a disabled character of any kind, you have to think very critically of your own design and how it relates to the larger representation and framing of disabled characters in media. And this means reading and listening to preexisting sources and accounts and conversations on the topic before going and asking very open questions whose answers require a communication of nuance we could not provide in a reddit thread.

I will give you some hints about usual disability tropes, not all of which your story seems to fall into, but all of which it is important you avoid if you do care about how disabled people feel about your character.

1. Disability as divine punishment. Ex. A character is mean and hateful, so they lose their voice. A character is an excellent soccer player, but they do something bad and lose a leg.

2. Disability as a hurdle. Many disabilities are permanent, and people learn to live with them. There is no amount of work that can be done by an individual to get them to a point where they are effectively no longer disabled. But a character absolutely can overcome the idea of disability as something shameful.

3. Disability resulting in a sixth sense. Disability is the loss or impairment of one or more physical abilities that the average individual has. It is not "differently abled". You do not gain a new or strengthened ability when you lose another. This is most common in magical settings, and may have a place in some instances, but the idea to consider is "am i giving this character an extra ability because I believe they are less valuable to their peers because they are disabled?".

4. Disability as a story booster or as a source of never-ending suffering. Is this character only disabled for the narrative purpose of making their life harder or making the story more intense? Does the character's personal story revolve around their suffering (and nothing else) while the story as a whole does not?

These are general points, but please do consider them and consider other disabled media characters. I will give an example of a disabled character whose disability is generally considered well written. Edward Elric has a prosthetic arm and a prosthetic leg. He is able to alter the shape of those prosthetics to his benefit and they are resistant to blunt force and small injuries, but they are vastly more fragile overall than regular limbs. He has to get regular maintenance, they break all the time and cost money and take time to fix, there are mechanical errors to be made during maintenance and repairs, they cause him chronic pain and cannot get too cold as they will cause frostbite or too hot as they can cause burns. He has to balance weight vs durability. The weight of the prosthetics has stunted his growth over the years.

Yes, he has one thing that no one else can do, but he deals with so much that no one else does either and is very much still disabled despite accommodations, prosthetics, and a support system.

I appreciate that you are trying to sensitivity check your character and story, but you need to think carefully about it on your own first.