Remembering why you play squash will do wonders for you. If the pressure of living up to unrealistic and self imposed expectations for results and improvement haven't completely annihilated your love for the game than there may still be hope. The burnout of sport is seen globally at every level in every sport, so don't feel that you are alone in your suffering.
I don't have many answers regarding this issue, but I have identified my own symptoms of burnout and have alleviated the stress thru a few means. I initially thought it would be enough to just give up on squash for the summer and hope to rekindle my love affair again in the fall.
But I have since realized that I just wanna play squash so I need to continue to play, but instead of focusing on all the things that cause me grief...like winning or losing, I just need to get out and enjoy playing. A couple weeks ago I went and played badminton and had an awesome time, it didn't matter who I was playing with, what level, points, teams, strategy, winning, losing, nobody cared, we were all there just to play...and although I don't really like badminton, I loved being out there playing it.
So the goal this summer is to improve and love every minute of it.