Its not good to hurt anyone's feeling no matter how much they may have hurt yours. Times a good healer as they say and it takes more of a person to let the bad things said to you go over your head, and it may even hurt that person who you want to hurt back because you are not biting back. Never lower yourself to other people's standards it only makes you as bad as them and i'm sure your worth more than that. Some people in life get a buzz out of hurting people with their nasty remarks etc and as much as they may hurt you, be strong, positive and simply ignore them.
Revenge and retaliation is not the anwser today, even if people do try and push you to the limit.
RE: Ending Friendships..
True friends would never make you unhappy.Sorry to hear your having a rough time of it, chin up!