My customers are paying, the unit economics work, but I feel stuck. I will not promote.

In April, thanks to my previous job, I noticed a pain point in a market that already has multiple unicorns, and I started talking to potential ICPs. I'm not sure of the exact number, but I did around 80 1:1 interviews and decided to start by narrowing my target ICP quite a bit. Within a month, I had built the product and started working on it full-time solely. Right now I'm acquiring customers in a super niche space, I think the total addressable customer size is around 150k people. I'm currently at 40k ARR. I haven't started paid user acquisition yet, people are coming in organically (SEO) and through LinkedIn outreach, and they buy a one-time license. After that, depending on which platform they want to make a transaction on, they may also pay one-time transaction fees. I don't know, maybe up to this point it doesn't sound too bad, but I feel quite stuck on two issues, and honestly I need some advice. 1- I want to build something big -at least reach a few million in ARR- but right now that feels very far off, and I don't know whether I should expand my market size to get there. I read Peter Thiel's Zero to One, and in it he advises that we should dominate a super niche market. I get that, but especially on LinkedIn, I keep seeing startups growing insanely fast and hitting millions of dollars in ARR quickly, and it makes me question myself: Am I really moving fast enough? Is this actually a market that can make me the kind of money that gets me to the level I want? That sort of thing. 2- I know VCs generally prefer a recurring revenue model, and honestly I think it does make the business more predictable, since one-time fees can make monthly revenue quite volatile. Do you think I should stick with the model that's currently working or should I push toward a recurring revenue model instead? What are the situations where a one-time fee model becomes an advantage/disadvantage? I'd rather not share details about my sector or product, since I'm not promoting, and the advice I get matters far more to me than any visibility/customer I might get. Thank you in advance to everyone who shares their opinion.