I had a similar running induced injury a few years ago. I think it was a tight psoas muscle. Stretching and ibuprofen were key to a speedy recovery.

+1 for foam rolling. I went to PT where I got some Theragun treatments also You can make your own for about $1, with an old golf ball and a jigsaw blade (and the powered jigsaw you already own). There is a youtube on it. I really like my DIY version.