Why not hire a personal trainer dedicated one-to-one for your swimming training? Search craigslist and should be able to get rate down to $35/hour, or $20/half an hour.
for people already have basic swimming skills, 4 one-hour session should be enought to correct strokes, breathing techniques, and diving! maybe summersault (flip-flop at end) if you practice more!
my personal trainer teach me life-guard skills in swimming and diving! Cheer!