How to control erection and sexual thoughts

Im on day 28, and my libido is high and Ive realized that sexual thought creeps into my mind randomly about this girl at my gym who i find attractive! Currently, as soon as i get erection and my mind wanders, i realize and consciously try to bring focus back to my work, but its getting very difficult to control. Do you guys have any practical tips? Also, Im really happy with the results so far, as I feel so much more energy and less social anxiety! I want to continue NoFap (No PMO) for atleast 90 days.