Trackball Practice in a FPS Game

So tried a bit of TF2 training with the new trackball mouse, was in the mood to shoot something... either I'm rusty for not playing for a year or so, or not used to this mouse yet... or I just don't do well at all in any tense/stressful situation that requires a split second action. Could be a mix of each... too soon to say.

Don't really plan to really go back to TF2, this was more of a test of how well I perform with the trackball than the trackpad, and if there's any improvement. Still can't aim very well and my anxiety is difficult to control to stay calm without the nervous habit of aiming too far or little in one direction I'm being fired at, or aim in a different direction altogether, or just hit the wrong button thinking it'll save me. Probably still need to mess with the in-game mouse sensitive setting till it feels right... don't know how long that'll take and if I'll be able to find it. Main problem would be my nervous habit of quickly going in the direction the target is at, over/under shoot my aim by a few pixels, miss, and get killed or take damage and hope I have a chance to fix my aim.

There is one thing for sure that I have to get used to, pressing the spacebar to jump with my left thumb instead of right hand fingers. When I was using the trackpad, I've grown accustomed to using my right hand middle, ring, and pinky finger to press it, index finger on the pad, and thumb between the left and right buttons. Also find it difficult for me to press Left Ctrl and Spacebar (usually Crouch and Jump respectively in most First Person games) with my left hand only as I can't free my right hand to hit the spacebar.

Right now have this scary feeling my life as a gamer may be over or still need to get used to this new hand layout for myself: right hand on mouse at all times, left hand on WASD, Shift/Ctrl, and Spacebar... or try to find an alternative for some of the controls to be more convenient for myself.

While I was playing TF2 for at least 2 hours, the part of me that hates losing or looking like a failure started to resurface and find that 'causes my anxiety. If I can find a way to control that fear and channel it more properly I may be able to perform better as a whole. Sadly it's a very old fear I have yet to attempt to face... 'cause I don't know how to face it. I don't know how others are able to stay calm and relax... would love to know, but I doubt it's anything anyone can really teach me or explain; I'll have to learn it myself.