Is there a word to describe the following emotion?

Question

Heiii lovely people, could anyone perhaps tell me whether there is a word to describe such an emotion. An emotion when you feel sad or disappointed due another person's success because: A. you desire the fruits of his success B. you could have achieved similar success yourself, but did not, due to your own volition.

An example of this would be: You have just come to a new social environment and have a premonition that all the people will not like you there and therefore you actively decide to not even begin to socially engage, although you would completely love to make friends. Few weeks later another new person comes to said social environment, he is more or less exactly like you. He however tries to make friends. He does it in the exact same manner as you would have done initially if you would have not deemed to not try to make friends.

This is my example of when the emotion, which name i am trying to figure out (or whether there even is a name for it), is felt.

I will also describe here my reasoning for why the feelings for "mystery" emotion arise. You don't need to read this as this is just my rambling.

In the above given example, i think that the emotion is combined of two parts: 1. Desiring what the other person has (pretty simple). 2. Second is much more complex, i think a disappointment is felt, because it turns out that your judgment about the world (which comes from your world view) is incorrect. Said judgment made you either to deny yourself joy or endure "suffering" ( As in the example above, where you forced yourself into isolation, due to your own volition ). When it is proven that your judgment is incorrect, then the reason to justify the "suffering" or denial of joy, which you made yourself endure, disappears. This makes you feel "mystery1" emotion, because all of the sudden for no reason you have been making yourself "suffer" or have been denying joy to yourself.

The feelings which come from reason 1 and 2 in my opinion make the "mystery" emotion, which name i am trying to figure out. :)

Thanks for the help :)

Answer 1

I suggest, wistfulness

The definition of wistful refers to being full of melancholy or yearning, or having a mournful or regretful longing. An example of wistful is when you look back on your past and wish you had done something differently.

http://www.yourdictionary.com/wistful

Answer 2

regret (mass noun):

a feeling of sadness, repentance or disappointment over an occurrence or something that one has done or failed to do

'he had to decline, due to his regret'

Source: ODO

Answer 3

Is there a word to describe the following emotion?

1. Desiring what the other person has (pretty simple).
2. Second is much more complex, i think a disappointment is felt,

From your description, I would say it's a feeling of envy and frustration.

• envy (noun) denotes a longing to possess something awarded to or achieved by another
• frustration (noun) a deep sense or state of insecurity and dissatisfaction arising from unresolved problems or unfulfilled needs.

Or would it be "jealousy"?

• jealousy denotes a feeling of resentment that another has gained something that one more rightfully deserves: to feel jealousy when a coworker receives a promotion.

Answer 4

You feel shame, or you feel

ashamed of yourself

for not having made an effort.