Sports Psychology Help?

Hi,

I was hoping someone from a sports psychology (or just any psychology I guess) background could give me some advice on this problem?

I have found that in my games, both online and OTB, I am at my most vulnerable when I think the game is won. I think that the hard work is behind me and then consequentially I stop working hard. I become blind to counter play and then I'm left reeling when I find myself still in a struggle.

Despite recognising this problem some time ago, I found myself falling like this again in a recent rapid tournament.

After 19....f6 I think I've won. Even though my opponent takes 10mins on his move and I remind myself that it's not over till it's over and I've lost many "won" positions before - After 20. Qd6  I go and make a mess with 20.....e5 and drop my d pawn with check making the game way more complicated then it should be. Reeling from my mistake, I later blunder a queen when we are both under 30 seconds and lose the game.

Are their any general or basic sports psychology methods that I could apply in these situations to help keep my head when I think I'm winning?

Thanks!

I've heard a simple tip that is supposedly common with masters, going away from the board and splashing cold water on their face to refresh themselves.

I asked a friend who are really into climbing, the similarity to chess being that climbers can climb 75% of a very complicated route with perfect technique and then they can lose focus on an easy move and fall off. He advised that I need to be more present and enjoy the process more. The process in chess isn't just achieving an advantage but also then pushing through and converting that advantage.