The problem is that even if she decided to stay with you, your jealousy would still be an issue. And even if you managed to keep it to yourself, it would eat you up inside.
Now that she's away, she will be meeting lots of new guys. And you're not there to hang out with her and be part of her life anymore. And to be honest, if she's telling her mother about this new guy, then he's certainly gotten under her skin. Long distance relationships are hard at the best of times - but in your teens they are even more difficult to sustain.
The only thing which may save you is seeing each other as frequently as possible to keep the relationship somewhat normal. How often do the two of you manage to see each other face to face? When will she come back?
Never regret anything that has happened in your life. It cannot be changed, forgotten or undone. So, take it as a lesson learned and move on.