Don't over do it! Have you tried getting a massage? I had some calf pain this past summer and massages helped. I had to ease into it very, very slowly.
Ya, do go easy. Hip flexors are no joke!!
Get good at the hip flexor stretch where you kneel on one knee. I actually stretch out my groin as well as my hip flexor by dipping, tilting, whatever gives me a couple different feelings of stretch in that whole area.
Also, quit running every day. I'd highly recommend going every other day if I were you.
As it happens my iliopsoas and hip flexor are hating me right now. Stretch! And don't overdo it until it improves. I am worried that you're still in pain even when not running for a bit. I go to a chiro to work on the area. Maybe try that or a massage.
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