Mario boards syndrome.
(We suck at encouragement)
Your story makes me glad I decided to pick up Shulk. To note, in Houston we have a player named Gnes and he plays an excellent Shulk, and also beats Sheik players regularly.
At a monthly, I got dead last because I was seeded against one of the best Sonics in Houston first match, and I felt I was ready for that tournament, so I know how it feels to get bodied, then be on tilt for the rest of the day.
Ironically, once I was out I had time to let the salt flow and then I had massive amounts of fun controlling the stream and having fun cheering for my crew. These things just happen, honestly. Experience helps us later down the line, so I'm sure next time you'll be "really feeling it" and wreck some faces.