A person who is often masturbating might feel inferior to others. Pre-dominantly, it can be a result of the feeling that they could not go beyond masturbating like others.
People feel helpless when they want to leave a habit they are addicted to, but they are unable to quit, making a person feel helpless. This arouses the mixed emotions curiosity amongst people suffering from helplessness and hopelessness, which can be dangerous.
It can lower their morale as each time they may repeat this activity, it could make them think that they will not be able to quit.
Some people might feel shameful, especially those who think masturbation is bad for one reason or another.
It could be one of the causes of depression if a person is addicted to masturbation and think they are not strong enough to hold themselves back. (See How does it feel like to be depressed?)
Intense mixed emotions
Having mixed emotions is the worst feeling as the effects of bad emotions are augmented when they amalgamate. It could make you experience all or a few of the emotions mentioned above.
This could lead you to experience bad feelings as dopamine instantaneously drops down when you finish masturbating. (See Why you feel tired after watching porn?)
Some people fill with remorse that they are not able to hold back and resist doing the masturbation.
How do you perceive masturbation?
The only thing that determines the masturbation effects is you, yourself. If you believe that masturbation is immoral and should not be practiced, you will be filled with guilt every time you do it. However, if your belief system interprets it as virtuous, you will not feel any of the above-mentioned emotions.
The negative psychological effects of mastubation
Masturbation and Anxiety: Is There a Connection? Does masturbation affect your mental health?