Unpicking or frogging hours of work may be a very frustrating work. This is why sometimes I prefer to use an unpicking tool. The pro of this tool is that in few seconds you can cut all your stitches and then just rub the back of the fabric to remove all the remaining pieces of thread. Be careful, however, if your fabric is not tight enough on your hoop or Q-snap, you can end of with a complete disaster, also known as a hole or a rip in your fabric.
This is what happened to me just last night (and this is the reason of the horrible pics, please forgive me).
Holy cow, I have just punched not one, but two holes in my fabric!! This means I have to trash all my hard work? No. The first thing you have to do is: don't panic.