Feelings, sensation or thoughts people have are temporary in nature. It comes from blankness, exists for a little time within your system and subsides again into a void. If you just perceive everything occurring as temporary phenomena mentally, see it, and let it go then there will be no issue. Slowly, all pain disappears.
Unfortunately, your mind does not operate in this way. Everyone reacts normally at their personal level to things they perceive. Without any question, you are programmed to be oppressed by your personal feelings without identifying who you actually are. You build limitation and separation walls with your beliefs and attachments. The majority of people live in this state.
The real way to dissolve suffering from negative emotions is to push them back into emptiness so as to identify your true self.
To release negative energy you need to see emotions clearly without being overwhelmed. Understand the emotion, nature, triggers and effects. Ultimately, release or separate emotions from your body. This is a fourfold process that includes clarity, composure, self-knowledge, and liberation.
The negative emotions will disappear or transform into something else. Otherwise, you can practice the next exercise.
Contemplate the opposite
Your mind will not hold two thoughts in chorus, especially the opposite ones. It switches between them but soon it gets busy with a single one. For example, if you feel anxious then make an effort to envisage anxiety and courage, fear will lessen. In case you feel sad then contemplate appreciation or if angry envision love and compassion. This will help to eliminate negative feelings from the mind.