The first step in approaching a negative situation with an optimistic outlook is to accept what you can’t change.
Once you’ve done that, you have 2 options: reframe ( look for an opportunity instead of ruminating on the loss ) or divert (shift your focus to something else).

Reframe or divert

One of the fastest, most effective ways to feel happier is to show someone kindness.
In a 2017 study by Oxford University, researchers found that performing acts of kindness for just seven days had a measurable, positive effect on well-being and positive social emotion.

Do something nice for someone else

Noticing and savoring the pleasant moments and thinking, "Wow, this is really great "can strengthen positive emotions.
In general, we tend to dwell on the negative side and not notice the positive things we experience.

Savor the good

Write yourself a message on a sticky note and attach it to your computer screen at work (an inspirational quote, a reminder to smile, etc).
Small reminders like these help keep positivity front and center in your life.

Set reminders

Most optimists have strong, supportive relationships. The comfort of knowing you don’t have to do everything by yourself contributes to long-term happiness.You don’t have to have a lot of them, but you have to have around you people you trust and trust you back.

Phone a friend

Thinking about what you’re grateful for can instantly improve your mood.
It works because our interpretation of events influences our emotions more than the events themselves.

Say thanks

Being positive doesn't always come naturally. If you want to reap the benefits of a more positive life, here's what experts suggest you do.

Savor the good

Similar ideas to Savor the good

On The Perception Of Negative Feelings

4. Practice gratitude for good things

Positivity Could be Good for Us