Hey, Gacela: Good to see you alive. My thoughts on self-publishing vs using an agent or a publishing house. Well...Yates was self-published, so was Tom Paine, and Piers Anthony decided to go that route after a while. I mention that because some people think it's somehow inferior to be self-published. But in the best of time, publishing houses have their own criteria, and they respond to the market, speaking of crap. Edgar Rice Burroughs decided to try and publish his stuff because he thought he could write as badly as the best sellers. Turns out, he was right. Ayn Rand wrote an unpublished short story, "The Simplest Thing in the World." (How did I get ahold of it, if it was unpublished. Leonard Peikoff, her literary executor published it, as well as her laundry list, and everything else written by her.) In it the author is being criticized by his friends and family--why not just write something popular and make a living at writing? He would try, and every time, he ended up writing something profound, epic, and heroic, i.e., not popular. It would be sort of like trying to write for Designing Women and the only thing that comes out is Gone with the Wind.
This isn't to say that you can't write brilliantly and get an audience for it. Ayn Rand is an example of that. Her first published novel, The Fountainhead, was almost rejected. The first reader put his job on the line, Random House reluctantly published it, and they did, as you say publishers do, killed it with lack of advertising. Only, it refused to die. People heard about it, word of mouth, and it became a bestseller. Suddenly, her earlier novels, "We the Living" and "Anthem" were published, and she could write her own terms for her next novel.
Fritz Leiber wrote for a writing buddy and he returned the favor. It was years before a magazine would print his stuff. And this was back when people were starved for fantasy, as SF was the thing, not fantasy, so most magazines were geared to that genre.
In today's market, you have the Big Five publishing houses, who only publish stuff that already sells. No room for innovation, and little for new authors. There are some small independent publishers, but they are quirky.
I've not made much from my writing, but I just bought a hardback book by a theoretical physicist with my hard earned royalties from Kindle. Before that, I published a couple of things and my earnings, combined, were about $300. My kung fu mentor and business guru tells me that I should write self-help books. It's good advice, but I nearly choked because I recall the scene in Newhart where he approaches a literary agent without telling him who is is to get his honest appraisal of his writing. His character made a nice income from self-help books. He presented "literature" to the agent and asked him--do you think I could be as successful as Dick Lauden? (Newhart's character's name) The agent snorted, "You aim high, don't you?" lol On the other hand, a philosophy professor wrote a logic textbook that was used in all classrooms, and he bought a condo in Hawaii with the profits. It all depends on your goals.
Personally, I write for myself, and the few adventurous souls who want to travel with me. I will probably do some self-help books, but that is a separate enterprise. I make my living from my tutoring (another entrepreneurial enterprise).
Suin, I think you're doing the right thing. See if an agent will take you on, but if they don't self-publish. A little marketing will generate a little income; a lot will generate more. And you can start the marketing very cheaply. For instance, you can say, in a post, hey, guys--I have three novels at Kindle, and I know you haven't seen how they end. Only $2.99 each; the price of a coffee at Starbucks and I won't call the police on you. So, what are you waiting for?