It would be helpful to find out a little more the symptoms you are presenting. The type of mood swings and frequency MAY indicate a different diagnosis. The mood swings themselves must be a difficult challenge,let alone the symptoms. I would first recommend an evaluation by a specialist. If you are going to continue with medication, a psychiatrist, if you have not already done so, would be the suggested doctor of choice. If you are currently seeing a psychiatrist it may not hurt for a second opinion. If you are being prescribed medication that does not address the mood swings, it is POSSIBLE you could be on medication that could exasperate the current symptoms.

Aside from the suggestion above, I would also recommend seeing what type of pattern, if any, you could see that presents itself. If you journal, you may discover times of day, sleep patterns, or situations that precipitate the symptoms. This may offer you an opportunity to predict and prepare for them.
It may be helpful to look at overall lifestyle changes that may help. Diet, exercise, and social pursuits may help.

If they are truly random and there is no predictability to them, the next action is to address the symptoms when they do surface. There is a school of thought referred to as mindfulness. It is a particular approach to coping with difficult emotions or situations. This is different then distracting yourself or thought stopping. It is a technique that trains one to accept and not fight thoughts. I would suggest doing some research on this for more information.
lastly, I would suggest talking to a therapist if symptoms persist. The therapist would be able to provide additional support and guidance to address these symptoms.