jealousy?

im thinking about jealousy a lot lately..more than i want to actually..is it a good thing to be jealous of other people? is it a bad thing? I dont know really..i guess it just kinda depends on what you do with your feelings..like you can be as jealous as you want but that doesnt mean you have to be mean to the person, or break there stuff and anything like that..no need to hurt them to make yourself feel better type stuff..that would be bad..that would be wrong..but being jealous and not acting on the thoughts isnt as bad..but maybe i guess its still one of those things that depends on the person.what they learned growing up..values, morals, etc, and so on..was i taught to be jealous? no..-sigh- i was taught to just want more..bigger..better..because i couldnt have everything i wanted..i had to share..i had to give up things, i had things taken away..and so i always wanted what other people had..i wanted everything..i wanted nothing..i just wanted i guess..and if i couldnt have it then i stole it..and then i no longer wanted it...maybe im thinking about all of this because of therapy..and the fact that she has a stress ball that i want and cant have anymore..she had two at first and told me i could have one..but i didnt want it at the time..i wanted to hold it and play with it, and dropped it a million times and watched it roll across the floor..but i didnt want to leave with it..and then she went and let someone else have it ..and now theres only one and now i want it and cant have it..i ask for it at least once a week and get upset because now i really really want it and she wont give it to me anymore ..how messed up is that?? the whole thing could have been prevented, i could have taken the ball when she offered it to me the first time..and i didnt..and now it just makes me upset..and it doesnt make sense?! it is completely my fault you know..i passed up the chance to have it and now it makes me mad..no im not going to steal it..but i want it so much it drives me crazy..and i think that the more i cant have it..the more i want it..but its not just material stuff that makes me jealous..im jealous of ppl who know how to talk and be heard..and i cant do it.im jealous of my sisters friend who attempted suicide..and im horribly ashamed of myself for that .but its just that she tried to do what i thought about nonstop and didnt have the courage to go through with it..im jealous of families that can get along and not argue..and actually like each other..im jealous of the kids that are saved from being hurt..when it feels like i was just left to suffer and manage on my own..im just jealous right now ..because i want everything i cant seem to have