The first reason is nonreciprocal love.
When love is articulated but it is not reciprocated it can lead to resentment and gives rise to bitter feelings. When the beloved forgets to include you in plans & actions – or is otherwise thoughtless; it hurts. This is the appalling truth that so often turns “love” into hate – the extreme bitterness and vengeance of love spurned. Even when love does not turn to hate, the sadness & hurt of unrequited love causes acrimony and unpleasantness in ones heart.
The second reason is jealousy.
This green eyed monster has the power to ruin a relationship and turn love to hate. The desire for exclusivity arises in romantic love which may not go down well with the other partner especially if it’s unreasonable in its demands. Turning of the lover into a police officer of the heart and trying to control the actions of one’s lover at all times can be suffocating.
The other reason of why love turns to hate is the chronic resentment over not being properly appreciated.
This feeling is poisonously disparaging in a romantic relationship. If you are giving something extra to the relationship then you would want to be recognized for it and appreciated.
Whatever the reason for your love turning sour, it is imperative that you keep in mind the fact that you have emerged smarter and stronger from the experience. Nothing can be gained by clinging to the feeling of hatred within you. Neither can anything be gained by retrospection nor analysis of what went wrong in the relationship. It is time to move on and look forward to the future which should be free from hatred and antipathy. Think positive.
You are now single and ready to mingle. So make the most out of your future and look forward to the bright moments that await you!