usta challenge team match just finished....

I always get prematch jitters.. and when my coach sends out an email on challenge matches.. i get nervous and throws my day off and the carefree life that i have is now interrupted. I don't mind losing if I gave it all I had and even playing up to par... but when my mind blanks, i get stiff, anxiety takes over, and I lose.. it takes me days too cope and I'm thinking i'm putting so much emphasis on tennis that i probably need to spend more time in my other hobbies (guitar for example) and hopefully this will reduce much of unnecessary jitters that are days away the match.... Some positive things that definitely work before a match and help me prepare for one so far are.
- breathing whenever there's some anxious thought that comes (the what if's and doubts that creep in)
- visualizing works but still finding a standard way of doing it that works for me so i can just make it a habit
- making simple game plan (usually is something like, get the ball back in play, hit deep, hit it to backhand etc..)

When i'm calm during a match and focused... usually everything else falls into it's place.... Which is why these prematch routines are important for me... When i'm anxious sometimes can help me play better also.. but the negative anxiety.. (example.. i'm confused, I might lose to this lower rank player, etc) get's me going downhill....
Hoping to get match routines down so i can gain confidence through it!! Will see what works, doesn't work..