Wear bike shorts for the next few runs. Use friction block in the future too. They are great also for toe blisters.
Monistat Care Chafing Relief Powder Gel, Anti Protection, 1.5 Ounce (447200A2) https://www.amazon.com/dp/B00AXVJF52/ref=cm_sw_r_awdo_R2BFTDXDB2S6YF2SP88E
Gold Bond Friction Defense Stick 1.75 oz., Soothes & Comforts for Daily Friction Prevention https://www.amazon.com/dp/B007VC9DKI/ref=cm_sw_r_awdo_D3SSW3WRNWJ6CXJR01XM
For chaffing this is the best goldbond by far....the powder and cream work but nowhere near as well as this.
https://www.amazon.com/dp/B007VC9DKI
Walgreens usually has them
Gold Bond Friction Defense saved my balls last year