Mouser, if you have tight groups, just not center of target, you might try a small sight adjustment to "move" the group over. If re-aligning the sites doesn't help, definitely use the chart posted by HossFly - I've helped dozens of people fix their shooting with that. First and foremost, though, is to have all of your basics down pat: Proper grip, sight alignment and breath control.
To help get over anticipation, get some snap caps (semi-auto) or empty brass (revolver) and have a friend mix-n-match without you knowing which are which. If you jerk upward while firing a dummy round, it's something you need to work on. Trigger pull should be like squeezing a lemon, smooth and steady, with only the front pad on the trigger face. Having dummy rounds will build consistency because you never know IF the gun will go off! If problem persists, you might want to take a tactical shooting class at a reputable school so an instructor can evaluate and help you.
Good luck and I hope you find an answer to your problem. I commend you on looking for an answer and not just thinking you're "good enough."
Malo periculosam, libertatem quam quietam servitutem." (I prefer the tumult of liberty to the quiet of servitude.). Thomas Jefferson
"All that is necessary for the triumph of evil is that good men do nothing."
-Edmund Burke, Loosely translated from Thoughts on the Cause of Present Discontents. (1770)