Everybody loses sometimes. Learning to deal with the nerves in a grappling match is really important, and I definitely second the "happy music" idea. I try to distance myself from the fight up to an hour before, then about 5 minutes before I'm up, I crank some hardcore and get myself ready to go, because I'm an aggressive fighter.
Everybody has their own solution to dealing with nerves, hopefully you're working on finding yours.
As for losing in double overtime, there are definitely worse ways to go. My first match ended with me getting caught in a triangle straight out of a takedown. The worst part was that I was up 10-0, or something like that. There was no reason for me to be aggressive, but I was and made a stupid mistake.
I've never done it since.
Sig by Toxic
Barnett - Toquinho -Werdum - "Nurmie"
Z. Gurgel - Morango - Rocha - Tiequan