@valeska Building a startup is hard. Here are a few things I would recommend:
- Try to find the right balance between working on your startup and enjoying your life (with friends, family, etc). Take time to do stuff outside of your startup. I'm saying this because you mentioned in a comment that you barely go outside of your room. It's not good for your mental health.
- Don't build to get into YC. Build because you're going to help people get a better life with your product. Once you're ready, go find some customers, build a waitlist, have them try your product (free or paid version but taking payments is always better). Stripe has different products so you get revenues quick (without integrating a payment getaway on your app). I think you need to be incorporated to use Stripe's products but not sure.
Now maybe you need a break from your startup. That's ok to take breaks don't feel bad about it.
Once you come back from your break, keep building and improving. Apply to other investors too.
Things that will attract investors and prove you're serious about your startup: incorporation of your startup, a dedicated team (even if it's just you), having paying users (even if you don't have a lot), growth of your numbers (even if it's a slow growth).