You have to decide how important this is to you. If it’s important enough, you won’t have any excuses. You’ll sit in the chair as long as it takes, you’ll write as many drafts as you need to, you’ll open yourself up to critique, you’ll work to improve your craft, you’ll persevere in the face of rejection. The best thing I did when I became serious about writing was to join a writing group. It’s important to find one where the members are dedicated to helping each other improve, rather than tearing each other down. I would advise any aspiring writer to join a supportive writing group, either online or in their community—and if you can’t find one, start one.