Pain near Groin

I’ve had this weird groin pain for the last month. I did a Solidcore class about a month ago - and noticed after it a tightness near my groin. It was kind of a dull pain so it didn’t bother me. In the last two weeks (since I’ve started marathon training) it’s gotten worse- not painful but more like really tight and uncomfortable. It feels worse when I do things like side lunges or ab leg lifts, and always feels uncomfortable the first two miles of my run.

I’ve tried Thera gun and heating pad - which temporarily helps but isn’t fixing it. And I think it’s getting worse. What should I do?