I thought I'd post a little hack I've found useful recently after little success peeing for 5 hours but felt desperate the entire time. Get a small towel/washcloth and soak it in warm (not hot) water and press it against the tip of your genitalia. I often, if am still struggling, combine this with running my hand under a cold tap in the sink next to me.

Hope those helps, and it could have practical uses if out in public bathrooms or in nature as you could bring a washcloth and a coffee flask with warm water in it.