*This website DOES NOT constitute treatment and only provides information and advice in a Q&A format. For treatment (therapy and/or medications) you must go to a licensed professional in your area. Please note that anything said here is not private or confidential, as this is a public forum.
Hello and thank you for using JustAnswer. Unfortunately the easy answer to your question is you cannot. You have to understand these issues are within her and that means only she has the power and control to stop and calm down. Just like you are the only person in control of your actions, she is the only one in control of her actions, which means she must CHOOSE to stop and calm down. This requires her to enter into treatment for her psychological issues which can be therapy and/or medications as a way to control her mood swings. Prevention of the mood swings is considered the most effective form of treatment.
You are most welcome. I wish you and your girlfriend all the best.
Please let me know if you have any other questions or concerns as I would be happy to continue assisting you regarding this issue.