If there are any benefits for swimming performance from creatine supplementation, they appear to be limited to a 50 meter sprint or a handful of 50 meter sprints with short intermissions. Excessive sprinting (over six sprints with short breaks) or too long of a break (five minutes rather than two) seem to not be associated with the benefits of creatine supplementation.
Using too much weight, too soon; always start lower than your expected ability and work your way up that first workout. If your form suffers, you are swinging the weight, or using momentum, this indicates you may be using too much weight. Greater momentum increases the potential for injury and reduces the effectiveness to the muscle group being targeted.