What to do with a strained hip flexor?

Stop running for a bit.
Seriously, running is very stressful on the body. You need to give it time to recover, and when you get back to it, don’t feel you have to push it. Recovery takes time and care.

If you are suffering recurrent injuries, perhaps you need to see a sports medicine doc., or at least, a good trainer to show you what is safe.

You have not been doing too well using your own judgment. I know you are impatient to get moving again, but at 13, you do not want to injure something seriously.

three months ago

two weeks ago

You probably should see a sports medicine specialist. The hip pain may come from a back problem.

I’d just go to doctor or professional in that field, so they can better examine you.

Some questions that come to mind for me is….
What is your diet like?
Look at your shoes? Do they work for your feet and body?
Do you only run?
How is your form?
Stretch or warming up before runs?
Considered trying other things to recover then get into running? Or perhaps other exercises that would compliment running. Swimming and cycling in gym is great as it really reduces impact. Building a strong is core is helpful.

I don’t know anything about you obviously so I’m just throwing ideas and questions around.

I would recommend quit running altogether.

What weighs more? 1 ton of feathers or 1 ton of bricks?

My point is, pick a set distance, and walk it. There’s less stress on the muscles, easier on the heart and you’ll lose the same amount of weight. And you burn more fat because the warm blood combined with longer period of time it takes to conquer distance is flowing more and therefore melting more fat.