What can i do to improve my thinking positively? i always think negatively, always worry and feel like i want to cry. my body feels tense all the time

Be a psycho!!!!: There's a pretty good book called 'Learned Optimism" by Martin E. Seligman. Also "Psycho-Cybernetics" by Maxwell Maltz. The basic point is that you CAN train yourself, actually train your mind to change a core attitude. It takes time and effort, but what doesn't? Like any habit, it will sneak back up on you, but once you are past the point of being captured by it, you'll just watch it in amusement