>>33140427I felt the same way a few days ago but that changed after I made a team from scratch and began playing Battle Spot Singles. You just need the proper mindset before playing.
Try to remember you're playing to learn and begin to accept that there is a good chance you will get bodied. If you're too focused on winning now, you'll just stress yourself out and lose motivation when you're defeated. Take notes at the end of your battles before leaving and make replays if necessary. I list an overall summary of a fight along with ways that I could have won the fight or sometimes ways that my opponent could have won. When I'm done playing, I review my replays/notes before deciding on what changes should be made on my team. Yesterday, I had some serious trouble with Mega Metagross so I tried using Mega Scizor and it's been going well.
Keep in mind that being on Showdown means you've also got quick access to damage calculators and detailed analyses of potential movesets. Don't worry about the timer and ELO ranks, don't worry about trash talk, don't be afraid to use copypasted sets, and just play the damn game.