by masquerade » Sun Feb 24, 2013 7:22 am
In life, there will always be people who we might feel the need to envy, and the reason for this is because we perceive them to have something that we feel that we ourselves may lack. This often comes down to low self esteem. Perhaps by building up your sense of self esteem, from within, without feeling the need to have it validated externally, you can overcome these feelings of envy. Your boyfriend could have chosen to be with this other girl, but he chose to be with you. If your self esteem had been higher, you might have taken his decision at face value.
I can't say whether or not you were right to split with him, as there may be other things going on in the relationship that you haven't mentioned here, but maybe if the split is final, you could use this time to work upon your own self esteem, and try to value yourself, just as you are? Therapy can help you to do this.
I take it that you didn't mean that you wanted to literally poison her, as this of course would be illegal.