This is the first sign! Listening to your gut is the first rule in life. If you have a feeling that you should not be in this relationship then listen to it.
You don't feel it anymore
If your partner does not let you express your opinions let alone listen to them, there is no point in being in a one way relationship.
He/She does not respect your opinions
If you feel suffocated and pried on all the time then you know what to do. Personal space is very important, no matter what your relationship is.
Your personal space is invaded
Unable to make your own decisions and doing what he/she wants is a violation of your independence. This should never be there in a healthy relationship.
You are being controlled
In a controlling relationship, if either or both partners feel they are doing things their own conscience won't allow, then you tend to hate yourself. Take this as an obvious sign.
You don't like yourself
If you cannot stay on your own even for a little while and you feel afraid of being along, it shows you are too dependent on the other person and clingy too. This is not healthy at all.
You are afraid of being alone
If your mind and heart keeps oscillating between your past and present with the same partner, or another, Comparing both all the time, ask yourself if you are fine in this bond?
You reminisce about the past more
Being in a superficial relationship is the worst of all. If there are no talks & discussions about anything and it is just physical, how are you in a relationship anyway?
A superficial relationship
If it is just you or your partner who is putting in all the effort in the relationship and you are not available for the other, then this is a one sided relationship which should end soon.
One way relationships