I know this reply is incredibly late (just rediscovering i had one of these lol) but i feel like this topic of discussion is always relevant. I hope this may still be helpful and that you're still writing!

People will say that you need to 'write for yourself' and you do. That's very important. I have definitely written things that I knew were only going to be for a niche audience at best and that was okay because I had a blast while I was working on it. That alone made it worth it. But there's no denying that we post and engage in the fic side of fandom to be a part of an active community and I totally understand the disappointment when you put a lot of time and effort and heart into creating something and it doesn't get the response you were hoping for.

Unfortunately, there's no magic way (that I know of) to turn those feelings off. What I can say is that sometimes all it takes is just having 1 person as your cheerleader. Do you have any fandom friends who read fic? A fellow writer you can bounce ideas off of and read each other's fic? I'd also suggest trying to be active in active fic community spaces! Signing up for events or fests can help get more eyes on your fic, promoting your works on twt, tagging @caratslibrary to boost them can all help. There's also a carat writers discord (you can find the invite link in my caard - https://cheapdate.carrd.co) with a great community!

If none of my advice is helpful, I suggest looking on r/ao3! There have been lots of posts about this and many writers have shared their experiences and things that have helped them. You may find something that resonates with you!

I hope you've found a way to stay motivated since you sent this and I hope you're able to take something useful away!