I met many ppl with this problem. Mostly to do with your attitude (not negative meant, don t worry). Try to think about what you re doing there- you re spending time on your hobby- and this just is something to have fun. This is something you can train on yourself (like a pain therapy, hrhr). For example if you re doing drills or so, let your kids play in the same room, talk with them while you re training. There are just a few seconds where you really have to concentrate during your game- just go around the table and get your informations. And if you have them all and know what to do: This is the one and only correct time to go down into the stance, do your warm up strokes-Ssst-plop ^^. You usualy need 15-25 seconds when you re going down to make a ball. In the other time you can do anything else my friend- look for the nice waitress (in this case your wife-don t make a mistake-LOL), talk with your buddies or your opponent.
Your problem is really often seen- and you ll see it very often especially at league-games or other tournaments where ppl going crazy about outside influences- in the most cases (my opinion) a great amount of billiard-players are just searching for excuses for missing the next ball-nothin else (don t talk about a guy who s really nasty or bad who s hollering at you thru a game!).
Don t set yourself to much under pressure- have fun my friend-even on patterns and if you re playing solo. And if you re playing with an opponent: talk to him while playin (about weather, work, women blabbla etc)- remember- you just need to concentrate when you re going down.
Everybody have to work with influences which are naturally given. Don t spend to much time on em. And if you re really enjoying your hobby and able to stop taking care about what other ppl could think about YOUR game or style of game many many things will become much more easier

I walked trhough this problem many times- but it went better after playing many tournaments and finding out for myself that it is just a waste of time thinkin about influences to my game- after i *understood* that it is all about myself in this game my game increased dramatically. (it really doesn t matter who s watching yuo or who is your opponent!) Just have fun and play your game-as long as nobody steals your cue while playing....there s no problem what should disturb you

I don t want to get too deep into psychological things here. But i hope you understood what i tried to recommend you. It will take a while, but it will work soon ,
lg from overseas,
and...have fun!
Ingo