Can't highlight a single line with text tool

Not sure what happened but I am unableto highlight a single line of text. When I try to select text using the text tool it highlights all lines in t he text box, rather than the single line/word I am tring to select. It is also treating colors very weird and will nto let me only select certain words to color, it is colorizing an area within the text box. Does anyone know how to fix this issue?