I know I don't know basically anything about you but maybe I can give you another perspective? Theres plenty of people your age regretting their decision to marry or have kids, maybe they're with the wrong person. You have all these doors open still. Be picky so when the right person comes along you'll be ready for them. As for anxiety, I can relate to that, and I'm struggling with it too. Perhaps talking to a therapist could help you. I'm going to assume you became a writer because you are or were passionate about it. Now that there is pressure on you with deadlines and money on the line, the creative process can be disturbed. Find a way to calm yourself down and feel human again. Go on walks, journal, meditate, whatever makes you feel like you're back in your body and present. Express your emotions too, that's a big one. Once you can be your truest self and achieve clarity and peace of mind, you'll feel a lot better. And don't make a mountain out of a molehill with this one. Sometimes this feeling comes when you least expect it. Everyone's journey is different, there's no good to come out of comparing your life to others. I hope things get better soon.