You might be stressed up about something, the best thing to do is to start nothing down things that come to your mind that have the power to change your mood. The continuous fluctuations might lead to your anger issue. I would suggest to work on those noted points one by one and resolving them will surely resolve your issue. For the time being, I would suggest you learn breathing techniques that help release anxiety. This will help you get control over your anger and other mood swings.