How can I keep my collar on my shirt from flaring out?

So my question is how can I keep my collar on my shirt from flaring out? I recently finished school and started a professional job and I find that my collars on my dress shirts don’t want to stay straight; it seems to flare out or stick out sideways. Sometimes, I’ll check on my shirt in the mirror at work and I see that it has an almost rounded shape to it. Any feedback would be greatly appreciated.

Thank you,
-Ryan