Je me suis endormi(e) en pensant à toi hier soir. Ce matin, je me suis éveillé(e) en pensant à toi en Français.
I beg to differ, Canard. à force de penser à toi would mean (s)he would be awakened by the thoughts of the other person. Yet what is said in the original sentence is merely that when (s)he woke up, (s)he thought of the other person. Hence I would keep T4U's translation.