I've experienced similar hip discomfort and switching to a mid-forefoot strike helped me too. It's unfortunate that sometimes it takes years to realize the impact of poor form. But hey, it's great that you found other activities like biking, hiking, and swimming to stay active! By the way, if you're into staying fit with alternative sports or activities, you might find some useful tips in this article about training for Ultimate Frisbee
https://playultimatefrisbee.com/the-ultimate-frisbee-workout-how-to-train-your-body-for-peak-performance-on-the-field.