1. Kübler-Ross model
a. Denial: In this stage the person is not able to cope with the reality of his/her breakup and denies it. The person thinks that their relationship is not over and may even call his/her Ex.
b. Anger: This stage is dangerous. In this stage the person realises that his/her relationship is really over. If the person is blameless for the breakup then this stage can take an ugly turn. During this stage, the person vents his/her anger on everything around him/her.
c. Bargaining: In this stage the person feels that anger is useless and starts negotiating with his/her partner to start the relationship again. A lot of swearing and promising is involved in this stage. Pleading and begging is the final part of this stage.
d. Depression: When pleading and begging doesn't work, the person sulks into depression. This is a dangerous stage for the person because this stage can not only affect his physical health but it can also affect his mental stability.
e. Acceptance: This is the final stage when the person realises that this world is not fair and his/her depression is not going to change it. So, accept life and move on.