I swear the mental blocks are harder on the parents than the kids. We hate seeing them suffer, amd would do anything to be able to help them get through....there are so many approaches to try, motivational cds, doc ali, not mentioning it, counseling through it, etc....but in the end all we can do as parents is think many a good thought that they get through it, and be encouraging and loving as they navigate through their fears. I remember reading how failure is the first step in success, and feel that this is true not only with this sport but in life. I cannot count all the times my dd has gone through mental challenges with this sport (and dont want to!), but I can say that because she has gone through them before, she knows "this too shall eventually pass," and does her best to stay patient through the process. This does not mean it is easy on her (or me, lol) during this time! I swear I have scars on my tongue from keeping my mouth shut at times when I know she doesnt want to hear anything from me. I have found what works best is to follow her lead. There will be days where she wants to talk about it, and days where she doesnt. I never ask; it is all child driven. One thing i have found that has helped my dd when she is down about it (on the down days, that is the hard thing with these blocks-everyday the mood seems to be different) is to divert her focus to one of the other events that is going really well for her, and talk about how far she has come. It is fun to talk about the past and bring up old memories. By doing this, it also quietly reminds her of how far she has come with the event/skill she is blocking, without touching on the skill itself.
Op and others, i hope your children get through these blocks smoothly. And for the adults can I suggest wine. And chocolate.