How do I fix my awkward smile? Is it because my mouth is too small? (photos)

So there first thing I would ask "is this your laughing smile?".   The camera (probably an iphone) distorts things a little bit some sometimes it's hard to give accurate advise.   I would look at doing 10 veneers to create proper proportions for your mouth.  Widening your buccal corridor a bit but at the same time decrease the "dominance" in the front of your smile.   So more balance would be my answer....but I agree with Dr. Faktor... you have great potential for improvement. 

You really do have some great potential for improvements.I would schedule a consultation to discuss the various ways to improve your smile.  Seeing from your photos your teeth are in pretty good alignment.  There are some length discrepanciesthat can be easily corrected.  When I look at your smile what seems to bemissing are your back teeth.  They need to be brought out more.In addition to that I would brighten them up and suggest a cleaner and fresher shade

Based on the photos, you appear to be a good candidate for porcelain veneers to improve the shape and color of your teeth, and ultimately your smile. Seek an experienced cosmetic dentist who has great photos and reviews.