a lot of really talented writers were always living on the brink until maybe a lot later in their life when their writing got more widely published and then they lived off the revenues of that. but how did they do that. usually it was their connections to other writers that thought highly of them that will either outright support them, petition for the king or royalty or whomever has the authority to award them a pension from the state to live off of, or get them a good publishing deal so their writing can circulate and make some money for themselves. at first writers came from nobility and had their families estates and wealth to support them in their endeavors. you would be at a great disadvantage to become a writer if you weren't one of them but if you could get some education and your first few attempts at writing something led to recognition, that might be your inroads to being able to writer more things. then you get invited to contribute to this or that journal and now you have a readership and an income from writing.

if somebody had original perspectives or ideas that others saw was valauble or a talent for expressing them then usually they could be a successful writer. maybe not in terms of how much money they made but you could get pretty famous and make lots of friends (and enemies too if your writing was controversial). but you had to be like the very most talented peopel with the highest ambitions.

thats more of a historical view of it now you could excel in one of dozens of established genres and so forth. how long you can devote yourself to finding enough success to propel you further along in writing would be determined by your funds. a wealthy SO could help, or not, since maybe they are just supporint a had habit thats not going to get you anywhere which you would've learned faster on your own if you didn't have that crutch. some ammount of assitence is helpful but you dont need 10 years paid living expenses to figure out if you could be the next writer for humanity or not. the people who really really really have to write usually will find ways to anyway.