I think it is very easy to get saturated when you are starting a business, many hours and not many expected results. Thinking about giving up is normal, what makes you continue in those moments?
I'm not building a startup, but I can offer some perspective on what to consider when you are about to quit, which can be applied almost anywhere:
If whatever you are doing is not giving you the expected results, what else is it giving you? There must be something that you are getting better at. What do you have now that you didn't have 6 months ago just by simply being in the process?