Why does Bitcoin-Qt not launch the program, on Mac I can't believe that I have lost my Bitcoin Wallet just because I clicked on the red spot on the window of it on my Mac. Or was this enough to loose it???

I think I have the address (does it start with a 1xxxx ?) and I have my password. 
Have I lost my wallet or is it just invisible? 

When I click on the Bitcoin-QT icon in my applications folder, nothing happens.
Right click the icon and quit Bitcoin-QT, then restart it. I have it on my iMac and occasionally it goes completely unresponsive. If necessary, force quit. See:

https://en.bitcoin.it/wiki/Securing_your_wallet

For instructions on backing up your wallet for future.