I would encourage you to do this gently with a set of dilators.
You might even want to purchase some lidocaine to use prior to using the dilators.
Start small, and gradually increase in dilator size. Usually when you reach the larger sized dilators in your kit, if you still have an intact hymen, or partially intact hymen, you will slowly stretch, or tear the tissue that needs to give in order to get in the larger sizes.
The dilation will also help with any muscle tension that you might also be having that is causing pain.