An ellipsis (plural: ellipses) is three spaced periods with a space before the first period and also usually after the last period. Here’s a line of dialogue from Ken Kesey’s novel One Flew Over the Cuckoo’s Nest that illustrates what ellipses should look like:
“Williams . . . I believe . . . you were supposed to have the windows of the Nurses’ Station polished by the time I arrived this morning.”
If an ellipsis comes at the end of a complete sentence, include the period that ends the sentence and the complete ellipsis, as in this sentence from Kesey’s One Flew Over the Cuckoo’s Nest:
“Oh, there are numerous possibilities,” the doctor says, sitting up straight in his chair and really warming to it. “Why, I’ve got a million ideas. . . .”
Notice that there is no space between the last period in the ellipsis and the closing quotation mark. If the ellipsis comes at the end of a phrase that is not a complete sentence, then don’t include an end-of-sentence period, as in this line, also from Kesey’s One Flew Over the Cuckoo’s Nest:
“Myself,” McMurphy drawls, “I’d be honored to work a skillo wheel. Had a little experience . . .”
So, that answers the question you asked, but the question you alluded to but didn’t ask—about how to break the habit of using so many ellipses—is an important one. So, I’ll cover that next.