It sounds like you could use some coaching, or at least some mental help with the game. A great book for the mental side of sports is "The Inner Game of Tennis". It really helps you to calm the mind and your thought process. It's worked wonders for myself and a few team members.
If you don't want to get a coach, then simply change your equipment to LD or non-LD ( the opposite of what you currently use). Some may find this counterintuitive, but it will force your brain to learn new concepts. When I get in a funk, I change something, be it equipment, stance, aiming method, to help myself get out of the process I've grown accustomed to recently. A coach will always expedite the process.
The more you continue to lose, the more frustrated you will become and you will mentally separate yourself from the game. It's very discouraging when it gets to that point.