What to do if I had an asthma attack at swim practice and I'm afraid to go back. Should I go or wait until I start meds?

Plan ahead. The chlorine evaporating from your standard pool can be a significant trigger for wheezing. We had a local er filled with regular folks when a chlorinator malfunctioned at a city pool, seems more of a problem with intensly sunny days. If you have an asthma tendency it is important to plan ahead, use your preventative meds & monitor your peak flows. With preparation all should be fine.
Wait. Your physician can help you solve this problem in an office visit or two. Then you can safely dive back into the pool. Make sure its the deep end.