I am having a difficult time starting urine flow and keeping it going. I have to bear down hard like I'm having a bowel movement and hold it to keep urine flow going. What can cause this???

See a urologist. Difficulty voiding in a women is usually due to one of several causes: UNDER ACTIVE BLADDER(due to aging, diabetes or neurologic disorders);BLADDER OUTLET OBSTRUCTION(due to pelvic prolapse,fibroids,urethral strictures or diverticula);FUNCTIONAL OBSTRUCTION due to several causes. **You need to see a Urologist for proper evaluation and diagnosis.
See below. It is not feasible to provide a meaningful opinion without examining you, however, your symptoms may be due to uterine prolapse. It would be prudent to see a gynecologist. You may consult this site for more information on this topic. http://www.mayoclinic.org/diseases-conditions/uterine-prolapse/basics/definition/con-20027708.