It's natural to feel upset. Don't be ashamed to cry or express your feelings. Remember letting your emotions out is healthier than suppressing them. It is possible to honestly express your emotions and validate your feelings without casting blame.

It’s important to try and contain this grief. It’s okay to grieve, but try to limit the time spent. Avoid letting the negative emotions spoil the following day. Try doing an activity you love, or surround yourself with people who usually raise your spirits.

Lastly, try not to lash out at others. The people you feel have let you down – or failed to recognise your efforts – are likely family, friends and acquaintances you will meet at future events.

Following a disappointment, it can be difficult to see beyond the immediate aftermath.

Ask yourself, ‘Will this matter one year from now? A week? One month?’. A lot of the time asking this question will bring you back to reality.

Talk to a rational, calm, sympathetic friend or relative, preferably someone who has experienced their own setbacks. Alternatively, writing your feelings and thoughts down can help express frustration, anger, fear, and other negative feelings, too.

You may be so focused on the unmet expectations that you haven't stepped back and felt grateful for the friends and family you have, the good times you shared, or the things that went right.

You can also turn your frustration inside-out. Make a list of all of the things you have to be thankful for, lessons learnt, or things you can do better next time. Chances are you have a lot to look forward to next year.

Okay, the event didn't live up to expectations. That's too bad. But luckily for you, there will be occasions to celebrate and events to plan in the future.

Make the most of the current summer weather. The warmer weather and longer days will give you an opportunity to discover a new passion, hobby, or pastime.

Go walking or cycling with friends. Join a summer sporting club. Go to the beach. Watch the cricket or tennis. Get into gardening.

By giving yourself space, you’ll find your excitement for future social events will build. It may even build to the point where it surpasses your current disappointment.

This is an important part of dealing with disappointment. If you can't undo what happened, rejecting the reality just causes pain.

Accepting what happened does not mean you need to like it. Rather, you just need to make space for it. Give yourself permission to be angry, upset, or disappointed by the experience, or the people involved. Try to learn from it and be better prepared in the future.

One final lesson you can take from your event is the benefit of anticipating disappointment. Envisaging potential negative outcomes allows you to develop a contingency plan, and reduces the shock and dismay if they occur. You’ll feel in control and prepared if things turn for the worse.

By using these tools, hopefully you can come to a place where thinking about a disappointing New Year's Eve doesn’t leave you angry, just a little bittersweet.

The SANE Australia website provides information, resources and support services focused on mental health.